I saw this on PumpkingxAngel's art book(btw how tf do you have more comments in there than me? I'm jealous of how much more attention your OCs are getting-) and I decided to answer this with my Mars gijinka since he's, imo, the most fleshed out of all my planet gijinkas

And before we start, here's a sketch of him I recently drew so you get the idea of what he looks like

And here are the questions

Also before we start, please note that I'm literally still developing Mars and I'm not exactly the best as character writing, so he is bound to change in the future
Just saying in case one of you goes "oh but you said he's like this! Stop contradicting yourself!!"
Good? Good
Now lets do some character building

1. What would break your character?

Emotionally? Well, simple, a good talking to
I actually answered this question last, so you should read all the other answers first before this one for the most context
But basically, Mars holds a great grudge against Sun and is too stubborn to let it go even after billions of years
This guy has pushed others away emotionally, he's basically like a rebelious teen. Perhaps all he needs is a good talking to, someone who emphatizes with him. But of course, since Mars barely opens up, actually talking to him will be difficult

2. Best thing in their life?

Mars discovering life is starting to develop on his planet

3. Worst thing in their life?

Mars' atmosphere being stripped away by Sun after his magnetic field failed, resulting in the disappearance of all his liquid water, the temperature dropping alot, and the death of the mirobacterial life that was forming there
(Okay, to make this sadder, Imma give more context. Earth and Mars actually started delevoping life around the same time, Mars being late by a million years or 2. Both kinda owe their creation of life not just on liquid water on their surface, but also Sun's energy. But after Mars' life was destroyed by the very same star that helped form it, it hurt him alot and formed his grudge and hatred that, even now, still hasn't stopped. I like tragic characters, okay. Idk how scientifically accurate this is, I still haven't done too much research cuz I'm so damn busy lol-)

4. An insegnificant memory that stuck with them?

One time, Jupiter slapped him after he snapped out of anger at the other planets. Its strange since he usually ignores the scoldings of his fellow planets or even Sun..

5. Does your character work or use hobbies to fill time between working?

As a planet, Mars doesn't need to work. Space entities like him don't really have jobs. But if he has a hobby, I imagine it to be taking a human or animal form and just watching humans fail at basic tasks

6. Something they are reluctant to tell others?

I don't think this is a fact even Mars himself knows, but I think its that he actually finds enjoyment in speading time on earth and looking at how life there has evolved. Of course, this is double-sided, as this reminds him of his own missed chance. He fantasizes how life on his own planet could have evolved. Though, Mars does hate how much humans have grown to be so ignorant of the well-being of their own planet(not that he cares about Earth. Again, he's very envious of her).
Another headcanon I have after answering a few more questions is that... he kinda wonders what would happen in he just let go of his hatred and opened up. Of course, he's stubborn as hell and probably won't reform without some serious effort from himself and others, but... its still a thought. I actually like this answer alot and I think this would be my official answer lol(the first one was just pulled out of my ass)
Idk, this was a hard question

7. Their feelings on sex?

This is a strange fact, but space entities like him can actually mimic human sex(In fact, these beings can actually be in romantic relationships. Just me justifying my ships-). To Mars, its just another weird things humans do not just for their survival in reproduction, but just one of those things humans do to pleasure themselves. But the thought of doing it himself... disturbs him to say the least..

8. How many friends do they have?

Most of the Solar System... sort of..
Mars is a loner, maybe with the exception of his moons, Phobos and Deimos, he would very much distance himself emotionally from the other planets as much as possible. I guess the other planets are more... companions to him. Idk lol

9. How many friends do they want?

A loner is a loner and he's content with what he has. Though, and this isn't really related but worth talking about, I bet somewhere deep down, he wonders what it would be like if he either never held his grudge or just let go of it. Maybe he does want to open up to his fellow planets and be truely happy for once...
Yes I already sort of said this on question 6, but that answer came to me as I was writing this answer. Idk things are weird-

10. What would they make a scene in public about?

I'm defining public as... you know, the human public. Mars is quite tempermental and isn't afraid to express his anger. Unless he's accompanied by someone who will and can stop him(like Saturn or Earth) basically anything that makes him mad will cause him to go apeshit. Of course, since Earth and a few other planets care about this kind of thing, they have drilled into his head to not make such a scene in public spaces, so he does try his best to not throw so many tantrums
Buuuut if he were to be accompanied by, say, Sun... wellll... self-control would just be thrown out the window-

11. What would they give their life for?

Thats a hard question... I don't think Mars can die per say. Unless his planet blew up or smth, at most he would just be greivously injured, but not dead. So thats what I'm going with. So what would he injure himself for.... again, hard question. I do actually think that, while he does hold a grudge against Sun and hate Earth(and, again, pushes everyone else away), as a whole, he still cares about the Solar System and would probably do something like this if it were threatened

12. Their major flaws?

I've already mentioned a few in some previous answers. For one, Mars has a short temper and pushes those around him away emotionally. He's been holding on to a grugde for a few billion years now and, while he thinks about it, he's too stubborn to let it go. And while as a whole he would protect his Solar System, he still can be quite selfish in choosing himself over others on smaller things. Mars is also brutally honest, not afraid to say some sassy comment that would no doubt probably hurt someone, so many's first impressions of him lack alot of sympathy. Though, for a positive trait, if he does actually care about someone, he cares alot. This is probably from his experience of loosing life on his planet(so maybe thats why he pushes others away..)

13. Something they pretend/try to care about

Again, Mars is quite honest, I don't think he would be the type of person to try to pretend to care about something unless specifically asked to. But I think for something he's trying to care about, I think that would be Earth's wellbeing. I mean, her humans are damaging her atmosphere quite a bit, not to mention they're hurting their bretheren which is the other life forms on the planet, but I guess Mars' hatred is overriding his sympathy

14. How different is the image they're trying to project from the image they're actually projecting?

Not too different, actually. As stated before, Mars holds a strong grudge, he is mad at Sun and he wants others to see that. The image he wants is tragically angry. While he communicates the angry part well, you have to learn a little more about him to see the tragic part

15. What are they afraid of?

I guess... loosing something or someone he cares about. It sounds cliche but after loosing something as big as life on his planet, its somewhat understandable
Also Earth's deep sea life. They can get FREAKY-

16. Something most people in their setting do that they think is dumb?

I'm not too sure about this one honestly. I haven't really developed this world too much so I don't really know any common things the spaces beings do other than... existing
So I don't really gave much of an answer for this

17. Where would your character be on a rude/politeness scale?

If 1 were very polite and 10 were very rude, Mars would probably be a 7
He can be polite if he really has to, but for the most part, he doesn't bite his tongue

Sooo.. yeah

Thats all for now I guess

I don't really have much else to say now other than I hope you didn't find my character writing too bad or basic

I mean- I am more focused on the character design after all

But yeah

Please appreciate my efforts--

Have a good rest of your day/night

K bai-