You're... not far off. Ayre is from Armored Core 6, she is a coral life-form. She "invades" the player characters mind, how things turn out depends on what decisions you make.

Coral grows naturally on planet Rubicon and is a sort of hive-mind. It can be used as an energy source, if you don't care that it's alive.

This version of her is from the route where she takes control of the ultimate coral-powered AC in order to kill the player. She's the final boss, a planet-sized conciousness controlling a mech.

Thiugh in the game, she never appears in any physical form, until a she rolls up on the player controlling this mech.