no idea what her name is, but I already have a few facts about her.

the reason she appears as both fat and thin is because of the way she controls her power.

Personality - she is a social kind of person who enjoys company most when everyone is happy and comfortable, and will try her hardest to make an environment comfortable.

Powers:
the more she eats and get's fatter, the more power she has to fight, though a she enjoys being soft for another reason.

she controls powers of light and crystals allowing her temporary elemental attacks based on refracted colors of light.

the heart crystals allow extra control of oppositions elemental attacks.

another ability she has is "baited breath" and "lips of honey" both are used for vore.