(credit to @xyzdragon1234) 

Name: Rio Ferrer

Age: 18

Alias: Zyanya

Hair Color: Stark White

Eye Color: Black (Glows White)

Gender: Female

Appearance: Same big bust as her sisters, has an eye scar on her right eye, and has a red crystal earring on her left ear which happens to be a gift from Ronin that she cherishes greatly.

Personality: Rio is quiet, emotionless, and low aggressive on the outside, On the Inside she's got a nice caring, and kind self on the inside when it comes to her friends especially when it's just her and her siblings. In a way, her personality is a lot like Akame's from Akame ga Kill. Also as the horsemen of Control, she is very good with words, and even without her magic, she can even manipulate people through words alone even using her voluptuous figure to charm men. Not only that she has a strange liking towards penguins, and just like her siblings she also shares the same cold personality towards her enemies she's got a sadistic side as well.

Guild Emblem Color: White

Outfit: Black and white female skintight leotard bodysuit, black Jeans, blue heeled boots, and wearing a white hoodie. 

Horsemen: Control

Magic: Word Soul Magic, Curse Warding Magic, Void Demon Slayer Magic.

Word Soul Magic: This Magic Attribute allows Rio to Manipulate her surroundings through speech. She can even other people and their magic spells and create a wide variety of Magical and physical objects of many elements. While the exact limits aren't currently known, this Magic cannot directly command non-plant living beings to die, and the amount used affects the range and how much it can counter another spell.

Curse Warding Magic: This magic attribute allows the user to create powerful curses that they can cast on themselves and others. It can even use the curses of the Demons of Tartarus use as well.

Curse Warding Spells: 

Exploding Life: The user detonates the power that they have bestowed on the target. Two magic circles appear around a dark mass in the target's stomach, meanwhile, the target's body swells as their magic power builds up inside of them. The target begins to shine right before it becomes a massive explosion.

Decaying World: The user generates numerous strands of runes that can dismantle and destroy opponents' spells, wrap around and bind opponents, and apply curses. While this spell is active, any rune arrays that are applied to or directed at the user become corrupted and weakened. However, spells of significant power and speed can be too large to weaken completely.

Unbound Slave: After placing rune arrays on another person's head, the user takes control of the person's body and forces them to unleash their magic. The magic is laced with curse power, increasing its strength.

Void Demon Slayer Magic Spells: 

1. Void Demon Rage: From their mouth shoot a giant beam of void energy from their mouth that is capable of destroying everything the their path including erasing things from existence.

2. Void Demon Imploding Expansion: The user creates a void orb from their hand and expands it and it's capable of erasing everything caught inside it.

3. Void Demon Healing Disator: A simple yet extremely potent and effective spell, it essentially allowed the caster to appear nigh invincible to those with an untrained eye. Whenever Rio sustained any form of injury, she enveloped herself in a blood-red aura of Void Energy. This aura of Void Energy was then used to heal Rio to an uninjured state, deleting garnered wounds and healing them back to perfection with negative energy. Upon using Void Healing, Rio was known to laugh hysterically, implying that each subsequent use caused the wielder to inch closer to insanity. As a result, Rio had been noted to sparingly use Void Healing unless the worst circumstances called for its use.

4. Void Demon Dark Orb: the user creates a small black hole of void energy that sucks in and destroys anything in a short range around it. The user can control the singularity's movement and launch it at an opponent. As the singularity moves away from the user, it grows larger and the range of its destruction expands. The singularity can carve through mountains in seconds. Additionally, due to the immense gravity, the singularity warps spacetime, enabling it to bend incoming attacks, even ones capable of cutting through spacetime.

5. Void Demon Presence of the Demon Queen: The user dramatically increases the strength of gravity in an area in front of them. Any objects in the area are slammed into the ground. It is capable of stopping a large projectile, bending magical light, and snapping trees in half.

6. Void Demon Evil God's Pressure Craft: The user pulls a large rock up out of the ground and then uses immense gravitational pressure to compress the rock into the shape of a large sword or make anything out of the rock. The user can control the sword or weapon made from the rock through hand gestures and can launch it at a target. 

7. Void Demon Bond Obliteration: Manipulates Gravity of things to create Miniature planetoids to strike and completely destroy their opponent. These planetoids are even capable of wiping off an entire nation off the map. 

8. Void Demon No Gravity: All the Gravity within a 500-meter radius is nullified and everything starts floating except for the caster.

9. Void Demon Alter, Reverse, Negate: The user has complete control over the opponent's gravity and as the spell says the user can alter, reverse, or completely negate their gravity thus they can freely and completely manipulate and control them. 

10. Void Demon I am Nothing: The user gathers all the remaining magic in their hand forms it into an orb and tosses it straight into the air. When the orb reaches space it explodes and rains down giant meteors of void energy capable of completely destroying an entire nation. If you want a full explanation of what it does then watch Arjuna's moves from the game Fate Extella Link.

11. Dimension Zero World of Nothingness: Purported to be one of the most dangerous spells in existence, it had the potential to bring ultimate calamity to all of Earth Land. The spell in question was World of Nothingness, a forbidden spell thought lost to the ages but happened to be uncovered by Rio and her siblings while they were being chased by the Xilian Empire. World of Nothingness was exactly what it implied. While devastating to say the least, casting World of Nothingness was realistically impossible as it required an extremely vast amount of Eternano to effectively activate, a feat no ordinary Human can achieve, even with the use of Second Origin. As a result, Rio desired freedom and the destruction from the Xilian Empire's clutches alongside her siblings combining all of their Ethernano together and cast this spell. By doing so, Rio would be allowed to cause Earth Land's destruction and ultimately erase it from the very fabric of reality. 

12. Dimension Zero Genesis Zero: The user first charges Dark Void energy on their fingers and casts open the Gate of Wraithwail, summoning many black phantoms (the "People of Nil") from the World of Nil to strike at their foes to the point of them being engulfed completely by their sheer numbers alone. This technique has been claimed to be capable of erasing a person's soul and their very existence.

Demon Modes:

Demon Force: Demon Force is the final stage of the Demon Slayer Magic, the embodiment of the ultimate power that Demon Slayers may possess, though the exact conditions to invoke it vary from person to person. When entering the said form, the user's body fully transforms into the element the Demon Slayer has in their possession, by saturating the insides of their body and the outsides with an overdose of Magical Barrier Particles. Such form change grants them the enhancement of their physical traits, like strength and speed, and demonic abilities they have, improving their combat capability significantly. Demon Force greatly increases the damage done by standard Demon Slayer Magic attacks and grants the user access to more advanced, powerful attacks. It also drastically enhances the user's physical prowess, making them far stronger, more resistant, and faster, and boosts their demonic power, prompting it to violently become visible, taking on the shape of a demonic visage; When used at the fullest, the generated silhouette seems to gain corporeality, likely as a result of the immense amount of demonic power employed. As the Demon Slayer's entire body turns into their element, after activating Demon Force they are virtually immune to physical harm. They can allow any attack to simply pass through them or simply absorb the attack; it is essentially a boost in the demonic properties that Demon Slayer Magic provides to the user.

Overdrive: Similar to Edens Zero By allowing the user's Ether power to flow throughout their entire body, the user can acquire a massive boost to their capabilities as well as being able to achieve feats with their magic they normally wouldn't have been able to. Along with this increase in power, the user also takes on a new appearance similar to that of the machine; having three-dimensional lines surrounding their body and covering their skin.

Demon Force Overdrive: Combining the power of Demon Force and Overdrive the user is granted an even more powerful boost in their magic power that it even starts affecting the Ethernano around them.

Endbringer Mode: In this mode, Rio is in complete control of everything. She completely and freely controls all people's force of actions and everything. Rio has been shown to offensively manipulate an invisible force in a variety of ways similar to her brother's dark gravity. This force can be used to damage her weak targets internally by simply staring at them. Depending on the situation, she can use this power in other various ways such as:

She has shown to cause her target to be crushed by an invisible force from over long distances. In order to use this technique, Rio appears to require a higher place such as a shrine or tower, the name of a target, and a human sacrifice. Rio forms a symbol with her hands and instructs the sacrifice whose eyes are closed by a white cloth to utter the name of the target. The sacrifice then dies and the target subsequently is crushed, preceded by a brief sense of "wrongness". This attack completely destroys the target's body but causes no damage to adjacent people or objects, even the target's clothes. While she is using this ability, the sacrificial people around her are blindfolded with a cloth. 

She has been shown to inflict damage by projecting an invisible force to targets she points at with her index finger which is strong enough to heavily damage, and kill instantly. She usually says "Bang!" while using this ability.

She has been shown to remove the heads of her targets in the vicinity from a short-to-mid range by using a sword; similar to her ability to crush her targets remotely, the people around her close their eyes with a black cloth. In this mode she calls this Force the "Force of Control"

Void Demon Queen Mode: In this mode, her complete manipulation of space is so powerful it rivals that of Ziggy's gravity from Edens Zero. She negates and crushes things with her gravity and can completely destroy anything her spacial energy touches. This is the true strength of the control horsemen that is Rio.