I'll bring the knives.
Use Vortex to group people up and for the vulnerability proc. Than just lotus, typhoon them. Assassinate and sig whenever you can. If you don't ever feel like fighting directly with her spender or you run out of mana cuz you aren't built in a way to support that, alternate between her dash and psithrust and just slash&dash through the trash.
Assassinate and psithrust are both great for positioning during the boss fights. Just hit either when you see any red arrows or charge ups to get behind them and they'll end up shooting the wrong direction.
her, X-23 and Doreen are my bane. others I either miss the timer (Loki I always miss the timer no matter what mental builds I use), or I die stupidly on what I would otherwise have done it (Human Torch, im SURE I have the dmg for it, but I just keep dying to Skull).
Some have been really fucking hard, and I actually got a rush out of doing it (I also raged hard when I failed with them). Nightcrawler was the big one, as not only is he not in the best place, but he is so unbelievably squishy. Luke Cage was much easier than I expected now that I switched to the dropkick finisher. Hawkeye was pretty easy once I sqitched to taunt arrow (20 point taunt arrow lols)
But yeah, Betsy, Doreen and X-23 are my bane, I just get overwhelmed by mobs either before Hydra, in which case I have to pop the ult (to be fair I pop ults for the hulkbusters on most characters), or before (or in adition to) Skull. Its strange because Psylocke and X-23 are 2 of my best characters 1 on 1 (well not so strange since the trial is a completely different situation)
Also, I pissed it with Wolverine (with no fucking legendary) and yet keep failing on Laura >_>
Still, Im now 42 heroes done on it, which is pretty cool I guess.
