General:
236B is your punish of choice
33k is your step punish of choice
66B will make him do stuff, guaranteed. -6 on block and they're in crouch state. Good option is to block or step after this is blocked.
6BK and 1K break turtles. Sometimes throws do too. Sometimes 4B.
When they flash red, a lot of moves formerly unsafe, become rather good. B+K,B ; 3B ; 66B+K,A,B ; 4AB
Cerv:
aB is -18 on block, blow him up with pretty much anything.
BBB - Last b on block gives you almost anything also
His hopkick is +2, it's a frame trap. Step clockwise and blow him up.
Super can be ducked on screen freeze as long as you haven't pressed butons
igdr - block and blow him up
gdr be - He's at huge advantage, hold block and wait for the BT B+K or throw mix and deal with it
Aeon:
BBB - A+B gi the last hit on reaction, easy. The whole thing is NC which is silly, and safe on block, more sillyness.
66A - Try to make him wiff this by back stepping and 11B. On block, you can press BB and will safely deal with most of his options (typically a second 66A), if you get hit, hold block a sec.
Nightmare:
Good round start is to run up to him and block, outside of Aga, his openers leave him open to stabs if you're close. Staying close to him, so his potentially safe moves (because of range) are not stab proof. AA BB will deal with his K's (kicks and fists).
Watch for gimmicks such as A+B gi, if you're stab happy, he won't use it often
For the most part, stab after everything until you get a feel for what is safe. He can't hurt you much if stab is blocked.
2A and 4K close range will make him turtle.
~Fei