Faust is the strangest character I've ever come across in any fighting game. His attacks are so strange too. He is not recommended to be used by anyone who is new to the game, but you can if you want. You might not get far though.

Moves List

Thrust, Pull, Hello!, Speak Up!, Hello Again! - HCF+K, B, QCF+P, QCF+P, QCF+P
What's Next - QCF+P (Throws a random item up into the air. Items are Mini-Faust, Hammer, Chocolate Bar, Donut, Bomb, and Meteor.)
Souten Enshin Rambu - QCF+S (From here, use P for a small attack, K for an anti-air, F,F or B,B to move in that direction with a strike or HS for a Going My Way.)
Going My Way - (in air) QCF+HS
Shower Hack - QCB+HS (close)
In Your Face! - QCB+P
Watch Your Back! - QCB+K
From On High - QCB+S

Overdrive Attacks

Super What's Next? - QCFx2+P (Does What's Next 5 times.)
Gamble Attack - QCFx2+S (This is a gamble as it says. There are 4 treasure chests. There is some way of picking, but it hasn't been figured out yet. When one of them opens, it will bring out a death figure or an angel figure. The death figure means that the super worked and Faust stabs the opponent for damage. If an angel comes, Faust gets blown up by a mini-explosion and takes minor damage.)

Instant Kill

Press All 4 Buttons to activate the "Attack Mode" then while in it:
This Week's Climax - QCFx2+HS

Combos

K, S, HS, QCF+S
Easy 4 hit combo for a character that has a really hard time with them.

Guilty Gear Mode Changes

Not much. Just increased stats.

Gold Form Changes

Gold Faust can be the cheapest character in the game. With infinite tension gauge and the ability to throw up meteors on every What's Next? and all five items being meteors on a Super What's Next?, this guy is unstoppable. Also, his Gamble Attack has a higher chance of hitting you (I think it's 95%-5%) and it does massive damage. All Faust has to do is constantly use Super What's Next? and it'll chip damage you to death.