X-Men: Destiny

This achievement is "Better than the Best."
Near the beginning of mission five after speaking with Wolverine he will tell you to tag along. In the next area a challenge to beat more enemies than Wolverine will begin. Simply beat more enemies than him and cheevo popped.
I used a full Iceman suit to help with mine. At first it was a little a back and forth but once I used X-Mode I left Wolverine in the dust.
*edit* I believe you also need more faction with the x-men for this challenge

I found this achievement to be not too difficult to get on a second playthrough using my powered-up character from the first playthrough. Doing it this way means you'll be stronger and have more powered-up genes and attributes.

When it came time to choose genes on the first playthrough, I chose all the ones for obsidian; ultimately this allows for the creation of the Obsidian Titan (RT + B when the blue bar is full). Level up the Obsidian Titan attributes as much as you can to allow for more time to be spent in Titan form.

For this achievement you'll need to have favor with the X-Men, so choose to do things that will gain you favor with them beforehand.

When the challenge starts, you'll notice enemies coming down a hallway towards the main room. Position yourself here, and switch to titan form. The titan does a powerful ground attack with a large area of effect radius so start hitting X when enemies get near the end of the hallway, and you'll knock them out as soon as they enter the room. If you've leveled up the Titan ability ahead of time, you should be able to spend nearly the whole challenge in Titan form.