I remember this well. there was two training sessions that gave me trouble, this one, and sub-zeros. Theres nothing I can say to help, but on the second pop up, you may want to move a step closer, and time the last part of the combo, right as the body begins to descend, or right after the body descends. You'll get it eventually
Slow your mind down, and execute.

I still can't get past that one freakin combo!.. its driving me crazy..

its back square...back square... square,square, triangle

If this is the one where you must juggle him 3 times in the air, but the last hit always seems to miss?

If so #1 Don't have him against a wall. (all this does is causes you to bounce away within the combo and causes you to miss.)

#2 Just before the last hit take a step forward. (This can be hard to time right but if you can it will hit and let you pass the session.)

#3 You can always leave the session, and come back later. you will start off where you left off. (After playing for hours it can become frustrating. Walk away from the game, take a break. This helps me out alot.)

That is my advise, hope it helps.

I finally got past that Raiden training session.. thanx for the input guys.. and I also just beat Scorpian to get Shujinko's spear move.. Cya online! my name is --Nate--