Some good advice already here. Just another way:

- Use max. awak. Cyborg Eddie. His past Power Ability 'Force Field' costs 4 and gives him an extra turn while charging the fury. Once you have it full, use fury (Time to Lose) to get 12 Power and 100% fury (and extra turn to all other allies). Doesn't matter if you kill all enemies in the first wave by using Fury. Having full Power you'll be able to complete the quest in the second wave.
- Then use Papa Emeritus IV's Power Ability, which costs only 4 and gives and extra turn to all allies. So now you can repeat, either Papa's Power or Cyborg's Power 'Force Field'.


And another alternative:
Angel of Death. Use his Power Ability, which gives an extra turn to self and target ally and gives 12 Power back if Perfect Bleed is on any enemy. Just equip Reaper Talis on him and you'll have it.