Marvel vs. Capcom 2

easy also. shows both 100/200

I made a Tutorial for this a 3 other achievements

There are many easy ways to get it but here's how I did it the first time:
-Plug in a second controller or play against a friend who is willing to help you for this.
-Take this team: War Machine, Iron Man, Cable. All 3 characters MUST have the Projectile Type.
-Fill up your combo meter up to level 3
-Be sure that the character you control is War Machine, he must start the triple Hyper Combo
-Execute your triple Hyper Combo by pressing LB+RB. It should go over 100 hits (mine did 101)

Edit: Easier to do against taller characters (Magneto, Anakaris, etc...) with a medium distance to them.

There's other ways like picking 3 Cable characters (yes it's possible) that will do over 100 hits (about 125 hits).