Here's some tips that were not in the walkthrough; subzeros combo:
Freeze your opponent, then run up to them and hit HP,HP,LP,LK,HK, back
and HK (Start holding back a second after you hit the first HK), you don't
have to freeze them, but if you don't they'll probably throw you when you run
up to them. (The combo is about the same damage as an uppercut, but a
lot more fun to do).
Mortaro: Keep jumping back and jumpkicking forward. Everytime
you jump back he'll follow, then when you jump forward he jumps toward
you and you HK him. Stay focused though because he'll transport himself
to the other side of the screen. It's still easy enough to beat him though,
just don't try using projectiles or they won't work, or sub-zeroes Ice freeze
will bounce back and freeze him.