Note 1: Your victim must be frozen.
Note 2: This code applies to the Xbox Live Demo version.

Anubis: Press X, Y, Left Analog-stick Up, A, R.

Lauren: Press X, Y, Left Analog-stick Left, Left Analog-stick Right, R.

Szalor: Press X, Y, hold L+ R, Left Analog-stick Down, Left Analog-stick Up.