Pretty sure you could do stuff with materia that exists in game this is just basically violating her with knights of the round. You travel the world you unearth rare materia, you've access or could have access to everything that is.
you got confuse, you got stop, you got silence, you got mini. you got revive. You got manipulate, you got morph. no need to invent new materia for your rape doujin. you might as well have just given him a smartphone.