In case you were wondering, I used lvl50 E7 Regime Superman (Kryptonian Suit +9, Promethium Longsword +1), Batman Returns Catwoman (Steel Claws +3), and Insurgency Batman (Bulletproof Batsuit +5). I built my team entirely through random packs, so forgive me for not trying to make the most strategic team.
Now for a play-by-play:
I start by juggling Darkseid down to about 50%, before the enemy (henceforth E) switches in Doomsday.
E gets some good hits in, getting Superman down to about 50%. I switch in Catwoman. I try to get some combos, but he uses S1, leaving Catwoman just below half health, block breaker coming in to play. He gets a few more hits in before switching in Deathstroke.
Deathstroke tries to start a combo, but I block, countering with Catwoman's S2, leaving Deathstroke at about 33% before switching in Superman, and immediately using S2 before E can use S1 or 2. Deathstroke is just barely holding on, at about 5%. He uses S1, healing to about