By the name of the thread...i thought you were referring to Sophia (In game she quotes "I guess i'm just a fatty").

Fayt is an alright character. Best moves of his are Sidekick (Great for Spamming), Air Raid (Knocking Down), and last...Dimension Door (Crowd Control). About Ethereal Blast...Its slow, but does a lot of damage, and needs some timing as well as distance to maximize it.

Maria is a hell of a lot more durable then Fayt in my opinion. She comes with two of her best skills already when you acquire her. Energy Burst and Radiation Bots are two hard hitting techinques, along with a decent controlling skill (Magnetic Field) for getting away from enemies that charge in.

I wouldn't say Maria's character is the best. I've just found more use for her then Fayt throughout the game.