It's all about tactics. And rng luck, as usual in this game.
- Do NOT hit Malak (unless you have to because he taunts. In that case use whatever gives the LEAST damage)
- Do NOT use aoe (unless it's the only move left or Malak is taunting. Then aoe tends to give the least damage)
- Kill the robots as soon as they appear
- Kill the prisoners closest to Malak in order left/right/left/right etc. Malak may absorb one or two
- When all prisoners are dead kill Malak
As usual you may need to do this a few times before you get it but this has always worked for me
Good luck
