Aesthetic by PokechuBirdie (thank you so much!!!)

I have made a more detailed, comprehensive and tidy bio for Sinewave in slide format. I can PM you the link; for some reason I can't seem to copy/paste into the book directly.

Note: This OC is a non-fandom OC made for roleplays, so some aspects may change depending on the rules/setting/scenario etc. of the roleplay. Please tell me if anything does not "fit in" with the setting/universe etc. of the roleplay and I can adjust accordingly (eg abilities, some aspects of timeline and backstory, though the latter would be mainly for the purpose of integration into the universe, not full-on giving her a different backstory). Can work in historical or modern setting; some aspects of the bio relate to one or the other. See the bottom of this chapter for some notes/clarifications.

----------Quote---------
"I am nothing if not efficient."

Name: Sinewave Londinium

Gender: female

Species: sentient automaton (was originally built as a generator; technically speaking she is still a generator as well as an automaton since she didn't lose any "functionality" when she was modified)

Age: construction was completed in 1757; her "birthday" (or rather, her first day of operation) was January 16th 1757 (age depends on what year the roleplay takes place; most steampunk roleplays take place no earlier than the 1800s)

Nicknames and monikers:
-Generator/Gennie (by her creator and his associates before she was properly named)
-Sine (by friends)
-Candidate Seventeen (as the 17th sentient automaton to undergo the Sentience Examination)
-Madam Generator (by those who knew her back in her early days among society; it started as a sort of sarcastic insult or form of mockery [for example, "Of course, Madam Generator would never approve of such inefficiency!"] as back then she was extremely blunt and argumentative and often came across as "high and mighty", however once she got better at interacting with people and gained the respect of those around her as they also gained a better understanding of her, this moniker became an acknowledgment of that respect. It is a moniker that Sinewave tolerates but does not encourage.)
-the Influence Machine (a moniker that came about in later years, Sinewave does not know how it started or who started it. It has a double meaning; influence machines are the class of generators to which Sinewave belongs, and this moniker came about as a result of Sinewave developing something of a reputation at some point. Again, this is a moniker Sinewave tolerates but does not encourage, as to do so would make her seem snobbish or self-centred.)
-Sparky (modern-day slang for an electrician)

Possible jobs: her job depends on what time the roleplay takes place (as well as the kind of setting of the roleplay)
-during the first few years after becoming an automaton she wouldn't have a job as she would be busy learning about the world and its people, though she could also take on some random freelance work during this period.
-during the first half of the 19th century, she would act as a sort of advocate or lawyer for other sentient automatons (or she would specialise in cases where they were involved even if not representing them directly) due to the growing population of sentient automatons and the need for them to be represented by someone who knows and understands how they operate.
-late 19th and early 20th century: during this time period, electricity is finally becoming more of a thing, and when the city implements a city-wide electrical system, she is naturally called in to help implement it. Essentially, she would be an electrician working for the city. During the late 20th century she would probably continue to work as an electrician wherever one was needed (whether it was still work for the city, or in people's homes). She would continue to represent/advocate for fellow sentient automatons when needed but at this point it would not be as crucial due to people having a better understanding of them and there being more of them now.
-since she is active during the night as well as the day, she may keep herself busy at night by volunteering for other random jobs that need doing at night (mainly applies to fantasy RPs)

Appearance: (see drawing below, though the drawing isn't that great) humanoid shape, made of a dark-gold coloured metal. Her eyes have gold sclera and (alchemically-crafted peridot) green irises, with dark silver pupils. She has a wheel which sticks out of her back (below her left shoulder); this rotates when she is generating electricity. She does not have hair, since she's an automaton; where one's hair would be (on the head), one can see intricate clockwork mechanisms, and in the front of her head, an old-fashioned lightbulb which constantly shines (though it flickers if she's annoyed or not feeling a hundred percent, "emotionally" or mechanically). This is all protected by a transparent bulletproof materiel (alchemically created). She stands at around 180cm tall. There is a clockface built into the back of her wrist.

Miscellaneous attributes: She speaks with a southern English accent; her voice is clear and only very slightly metallic.
She is warm to the touch due to the electricity running through her (the only part which would not be warm is the wheel on her back)
One can hear the ticking of her clockwork heart (which is located lower down then it would be in s human due to her unusual internal structure), as well as the sounds of her various other mechanisms, if you get close enough, though it is not particularly loud.
She needs to recharge herself approximately every seven hours; this assumes "normal" activity however as exerting herself or using her electricity will obviously drain her charge more.

Clothes: she wears a long-sleeved white shirt with a collar, a long sleeveless black button-up jacket with gold trim and a gold sinewave pattern around the middle of the torso, white pants and black boots with gold buckles. She wears the key to her clockwork heart on a thin silver chain around her neck.

Personality: strong sense of duty and is very patriotic towards London/England (or whatever city/country the roleplay is set in), always up for discussion and debate (though stubborn and argumentative to a fault at times), a proud individual as a result of the aforementioned traits (and because of her history). Logical and practical, but also philosophical and contemplative. A bit unsure of her abilities (post-modification).  Can struggle to understand some emotions sometimes and gets annoyed when others can't seem to observe hers due to her being an automaton. Can be a bit of a perfectionist or a "control freak" at times especially when performing some task which involves the natural skills that she has always had, some task which she knows she is likely the most qualified individual to perform (in the immediate vicinity) or that is the kind of task which her mind was practically built for. She is also somewhat obsessed with efficiency, in all things (as efficiency was the whole reason why she was built). She has extremely high standards with regards to efficiency which apply to herself and those around her. She has very little tolerance for blatant inefficiency and will have a hard time respecting a person who makes no effort to be efficient in the things they do when they clearly possess the means and knowledge to act in a more efficient manner. She does understand that humans are prone to certain mistakes or lapses in judgment which machines are not, and she will generally forgive them. However, this only applies to genuine mistakes or accidents. If someone willingly does something mean, bad, selfish or otherwise problematic, and she is not satisfied that they are genuinely remorseful, she will have a VERY hard time forgiving it, even if it is that person's first "transgression"; this is because in doing so, this person has shown that they are perfectly willing to knowingly go against the "greater good", which goes against her fundamental principles and motivations. On a similar note, Sinewave can also struggle to forgive her own mistakes, genuine and understandable as they are, and will dwell on alternative paths she could have taken (which in reality may not have been possible or have ended up preventing the mistake anyway) and ways to prevent the mistake in future.

Backstory: She was built in 1757 by a genius inventor of some rank. She was originally built as a generator, not a full automaton in her own right. The reasoning behind her creation (as sentient) was that she could communicate any issues, necessary adjustments  or suggestions to her creator.  She was constructed such that her "soul" (or whatever the source of her sentience) combined with her various mechanisms, could generate electricity (another reason for her creation-her creator came up with this idea as a possible way to generate large amounts of electricity-by combining machinery with a soul to drive said machinery), which was used to power the inventor's workshop/house. She was still humanoid back then, but connected at the shoulder blades to wires which sent her electricity to whatever devices and machines required it. She stood upright in a transparent circular chamber with levers, dials and such to control and direct the power when needed.
In the beginning, her only communication with her creator was related to her "job", but over time they developed a relationship akin to that of true colleagues. Her creator would ask her advice on various things (related to his/her inventions, or anything else they wanted a second opinion on), especially as she was able to perform calculations beyond a human's capability, for example, or predict problems that a human might not consider. One of her defining personality traits, developed over time, was her ability to see things from many points of view, and her curiosity to understand perspectives that she might never have considered, even if she might not agree with them (this ability to see things from different "angles", combined with her mathematical talent, is why her creator decided to name her Sinewave). This, along with her philosophical nature (developed over the hours she spent thinking alone when her creator was not there) led her to enjoy true constructive debate, for its own sake. She and her creator would have long debates, sometimes of a philosophical or otherwise abstract nature, sometimes not, which would last long into the night. 
Eventually, as the Industrial Revolution progressed and machines became more prevalent, so too did the need for a means to power them. So great was her potential (pun intended) that Sinewave's creator knew that it was practically wasted on just his/her one home. The two of them agreed that it would only be logical to expand to others, if Sinewave could handle it. So it was that the system that Sinewave powered was expanded to the homes of her creator's neighbours (also individuals of some rank). These occasionally visited Sinewave's creator's house, and were fascinated by her. She enjoyed fascinating discussion and debate with them at these times, and they enjoyed it also (plus they sought her counsel on matters occasionally also). Eventually, as the years passed, the system grew, and eventually Sinewave provided power to more than just homes. Certainly, there were times when she really had to push herself, like during winter when the cold weather and higher demand made things feel harder. But she felt a sense of duty to those for whom she provided (especially as she saw more and more little lights out the windows), for it was what she was created for, after all. Plus, it's not like her life was miserable or anything. She was fascinated by the abstract and by the debates she enjoyed with her creator and other companions. She was simply providing a service, as any other individual would. Her existence was only known to those original few individuals, however, for obviously they didn't want tons of random people showing up at the doors, and also her creator felt that maybe it was best if the ability to use actual souls as a means of electricity generation were not widely known (for ethical reasons, and also because they could be in danger if the wrong person knew about Sinewave and the technology used to create her).
The years passed and her creator grew old. The visitors grew less frequent as they too grew old and could not venture outside their homes as often, and some of them died too, of course. One day, Sinewave was "awoken" to her creator carefully opening the transparent chamber in which she had spent her entire existence up to that point, and over the course of an hour or two, disconnecting her from the system, which now spanned a decent portion of the city (note: whatever would make sense for the roleplay). Upon realising this, Sinewave demanded to know what was happening, fearing for what would happen to the people when deprived of her power; she had a duty to her city (or her section of it, anyway) which she watched from her chamber, which was situated high up where she could oversee the whole workshop and the city through the windows. She was told that there was no need to fear. By this point, regular, non-sentient steam and aether generators were becoming more prevalent. They weren't as efficient or reliable as she had been, said her creator, but they would do the job, so that she no longer had to.
When next she awoke, she found that several adjustments had been made to her mechanics and her outward appearance, as a result of no longer being connected to the machines she used to power or stuck inside her chamber. Her creator knew that he/she didn't have much longer to live, and wanted to repay Sinewave for her service over the years. Plus, he/she and the other humans wouldn't be around forever to keep her mechanics in order or to keep her company, so this was the only way to prevent such a fate as would've befallen her otherwise. Not knowing what her purpose was now that she was no longer the thing she had originally been created to be and no longer had the duty of bringing light and power to her creator, her other friends, or the rest of those she had served, she asked her creator what she was to do with her existence now. Her creator's last words to her were, "You'll find it out there, I'm sure. Your power is truly yours now, Sinewave."

(Note: some aspects are deliberately vague so that Sinewave can be integrated into the universe of the roleplay)

Worst fear: That electricity might ever be deliberately used to do harm.

Abilities/skills: stronger than the average human (though not to a significant degree), very sensitive hearing (though this can also be a problem in certain situations since she struggles in noisy environments), electricity generation (has two sockets on her back below her right shoulder so she can power things), electricity manipulation (she does not use this very often and does not know how far she can take it since it could potentially be dangerous to test her capabilities), extremely good at mathematical calculations and thinking/logic involved in mathematics, good at thinking on her feet. Her memory is nigh flawless; she recalls every day of her existence in perfect clarity (this is a double-edged sword however as this includes both positive and negative events, meaning that when said negative experiences are brought up she will recall them in perfect clarity which would obviously severely affect her, sometimes to the point where she may freeze in place and be unable to focus on anything else in extreme cases. Additionally, her "inability to forget" is another major reason why she struggles to forgive others.).

Weaknesses/flaws/limitations: the cold (she's clockwork/electric hybrid, after all), loud environments, chaos and chaotic environments, emotions can be a bit confusing and awkward for her to process, she's uncertain about actually using her electricity because of how dangerous it could potentially be, any repairs/adjustments/upgrades could be difficult because of the way she was built and the lack of truly qualified experts in the field of electrical science (during the 18th/19th century), she is not as physically strong as a lot of automatons are (again, due to the limitations her creator faced during her "conversion/upgrade" process due to her internal mechanics and how she was built), she is heavy (heavier than a human of her height) and is not agile.

Likes:
-efficiency (and people, systems and things which demonstrate this principle)
-philosophy, discussion and debate
-a genuine challenge (which would present an opportunity to demonstrate or expand her knowledge, skills and/or potential)
-being helpful/useful
-chess and other board games, especially when her opponents are intelligent people who could present a challenge
-electrical experiments/projects, especially those involving electrical devices from her period, or those which allow her to utilise electricity/circuitry in new and creative ways
-efficiency
-her work and the good it does
-lightning/storms
-modern art (ironic, I know. She likes considering the deep meaning behind each piece; it ties into her philosophical nature)
-reflecting on people she knew or positive events from her past
-efficiency (did I mention that?)

Dislikes
-inefficiency (and sources thereof)
-immoral people/things/principles etc.
-her limitations and the problems that result from them
-memories of Bad Things, or even the mere mention of said Bad Things which can trigger those memories (eg. the Luddites, Edison and the War of the Currents ESPECIALLY, the London Blitz, etc.)
-the idea of electricity being harmful and the negative consequences that its use has had (eg pollution)
-people who see her as a "lesser" being due to being a machine, or who dismiss her or think her obsolete (in modern times) due to her antiquated technology
-winter (she will leave the country for a while if it gets really bad)
-when she sees some electrical work that has clearly been done by an amateur (it concerns her, yet there is nothing she can do to prevent said amateur from causing more problems via their poor work elsewhere)
-irrationality and unscientific thought,  especially when it causes harm in some way or is used to justify harmful things
-when history is disregarded or when false beliefs about historical events/periods are spread
-the fact that humans don't seem to be too good at learning from said history

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"'Sentience' and 'humanity' are not synonymous. If you cannot comprehend this basic axiom of existence, then you have no hope of even beginning to understand me."

NOTES/CLARIFICATIONS/POSSIBLE CHANGES
So, some people may be thinking that this character is bending the rules of steampunk quite a bit, so I thought I'd better add some notes and clarifications here.
1. The timing of her creation. Steampunk takes place during the Victorian era, but she was created in the middle of the 18th century. This is because this timing allows for time for all the backstory to happen (since from her creation, to the expansion of her system, to her eventual modification spans a number of decades). When I apply to roleplay, I will ask for a year in which it is set so I can figure out her age. It does not matter if this year makes her over a hundred or something (in such a case, I could say that maybe her creator intended to make her into a full automaton, but was not skilled enough, or died before he could do it, and her modifications were later performed by his child/apprentice/student, or even your OC, etc.).
2. The main thing I feel I should address is the whole "electric power in steampunk???" thing, plus some historical/technical clarifications. Electrical science was still a developing field during the 18th century, and it wasn't until the first electromagnetic generator was invented by Faraday in the 1830s that electricity really became practical. Sinewave is a member of the class of generators that came before Faraday-electrostatic generators (she is, more specifically, the kind known as an "influence machine"). The first influence machine, according to Wikipedia, was built a couple of decades after Sinewave was built, however, due to steampunk having technology which is quite advanced compared to what was actually available at the time, I'm hoping you can give me a little wiggle room here (same story for the lightbulb inside her head; besides, given my references to aether and alchemy, I imagine that in the steampunk universe, there would probably be some kind of aetherial or alchemical lamps, and the existence of these would cause the electric lightbulb to be invented earlier, even if the first lightbulb WAS the one in Sinewave's head in this case). These early generators weren't very efficient because although they produced high voltages their current was low, so they weren't very practical outside of scientific use. Sinewave started out this way, however, over the course of her mental and existential development, she developed a true "will", and this drove her on to push herself beyond her initial technical limits (the way I like to think of it is this: her mind drives the voltage, her will drives the current). Hence why her ability and output increased over time, and to the point where she could actuallly produce practical amounts of electricity. This is why, when she was "relieved" of her duty (when she was modified), the use of electricity would've gone down since there was no longer a way to generate truly useable amounts. Hence either the system that Sinewave powered went out of use and they reverted back to using steam/aether/other sources for power, or her creator (plus their colleagues) modified the system to run using a number of steam and aether driven generators. Not as efficient or reliable, but since the system would probably only span a particular district or two in the city, it wouldn't be a massive hassle.
2.5. If this really bugs you, or even if it doesn't but you want to do something a little more historically accurate or involve real historical figure in the RP, I can push her creation forward a bit and she could be the creation of, say, Faraday, or even Alessandro Volta, since I did an assignment on him in year 11. (The latter case would mean she was built in Italy, and there would be a few other minor changes as a result of this, but this would also be an interesting take on things, especially if, say, she travelled to London after the modification process in order to meet more sentient automatons, for example).
3. Regarding the "20 years have passed" thing, this is not set in stone by any means! I think it would be really interesting to RP scenarios where Sinewave has only just been modified, for example. Or, you could change the backstory a bit so that her creator died and, without a successor, so she was just left to generate in her creator's workshop until your OC discovers her somehow. That would be an interesting scenario. The 20 year gap is just for general RPing, to allow time for her to "settle in to life", get herself recognised as a citizen, study and get a job, etc. again, it is not set in stone.
4. I am currently writing a story that goes in-depth into Sinewave's backstory, and the process of developing sentience, so keep an eye out for that if you're interested!
5. Finally, some clarification regarding the use of electrical terminology. A lot of the terms and units we use today weren't in use back in the Victorian era, obviously. I'm not quite sure what some of the equivalent terms which would've been used at the time were, however, as I couldn't find the earliest use of some of them. For example, Sinewave has a capacitor inside her, though this is obviously not the tiny thing you'd see in a circuit board today! The earliest device which could be called by that name was the Leyden jar (hopefully I spelt that correctly!), which was invented in the first half of the 18th century. Sinewave would have a similar but more refined device, probably made out of some kind of metal (or even alchemical glass like her head dome) rather than just normal glass. I don't know what the general term used for these devices was at the time, if there was one, so I'm just going to call it a capacitor since I can find no earlier term for such a device, if I need to refer to it. I'll be sure to clarify what I'm talking about if I need to use terms which are different to the modern ones (eg potential difference instead of voltage) during the roleplay, if it comes up.