Yang is friendly and outgoing, and a fan of bad puns.  She has the ability to inflate herself like a balloon, and enjoys testing her limits, showing off, and competing with others.  She's willing to inflate others or teach people how to inflate as well, and is willing to try inflating any part of her body with a little encouragement.  She is a graduate of Beacon Academy, an incredibly powerful fist fighter, and works as a Huntress, but she's more famous for blimping up in public.

Outgoing and pneumatic, in more ways than one.

"Saber of Red" and Servant in the Holy Grail War, Mordred is prideful and haughty.  She does not even think of failure, boasting overpowering words from a clear and unclouded voice that shows dignity befitting of a king.  Due to a wish from the Holy Grail, her Master has transformed her into a living pool toy, able to be inflated whether using an air tank, a pump, or simply via the Command Seal of his Master.  While she outwardly denies it, Mordred secretly enjoys being inflated.

You used the power of the Grail for THIS?!

Blake has a mellow personality, and is cool, reserved, and serious most of the time.  A bit of an introvert.  She does have humorous side, however, in the form of dry jokes and sarcasm.  She is an avid reader and, as a hobby, has taken to writing stories about body inflation and expansion. She also engages in inflation herself when alone or with close friends, and is willing to share her methods or inflate others if she trusts them.  A graduate of Beacon Academy, she works as a Huntress.

Author of *those* sorts of fanfics.

Weiss is nice, but can also be a little bit prickly in personality.   She is irritable and confident in her abilities, though also acknowledges her deficiencies and the need to hone her skills further.  Her confidence in her skills and intellect often comes off as arrogance to others.  After warming up to people, she places a great deal of trust in them.  Due to an accident involving Dust, she tends to inflate during periods of emotion.  A graduate of Beacon, she works as a Huntress.

You'll be filled by air by the heir apparent

Selene is ordinarily a shy and nervous young woman, but tries her best to be friendly despite this.  Selene has a secret: She has the curse of the were-loon, and can will herself to transform into a rubbery, inflatable monster girl.  When turned into a were-loon, Selene is arrogant, outgoing, and dominant, toying with people and inflating both herself and them.   She can return to her normal human form by willing herself to do so.

A timid woman, touched by the were-loon curse

Eternally optimistic and completely lacking in sense, he can be called "curiosity in human form."  With or without permission from his Master, he will often leave to indulge in the pleasures of the world.  He greatly enjoys being inflated like a balloon, whether using an air tank, a pump, or simply via the Command Seal of his Master.  He does what he pleases without regret.  His conversations, through no ill intent on his part, have a way of meandering toward maximum social awkwardness.

Indulging in the stranger pleasures of the world.

Formed from an experiment which fused Yang (from RWBY) and Mordred (from Fate), Moya is cheerful and energetic, but also prideful and haughty.  Flippant, never thinking of failure, and extroverted, Moya has a regal bearing... most of the time.  The experiment which fused Moya together also allowed her body to stretch and contort like elastic, as well as inflate.  As Moya is two people merged into one body, she refers to herself as "we."

A stretchy, inflatable tomboy fusion (but why?)

Ruby is open and honest, to the point where she has difficulty picking up on social cues.  Despite her naivety she is intelligent and caring, and can be dependable when needed.  Socially awkward but far from shy, she becomes very good friends with people who share her passions and enthusiasm.  After discovering a "unique" application of her Semblance, she has taken to inflating herself with air and other gases for fun.  A graduate of Beacon Academy, she works as a Huntress.