Quick tip to beat nightmare ultimate evil, place your characters so 1 is in corner, then others so that it is impossible for him to reach your safe archer/swordsman with +1 range weapon, since the ultimate evil takes 2 spaces he will teleport around trying to reach your final person, you can safely beat on him without reviving your others, IE you have a corner with 4 spaces :: place your safe hero in top left corner with your meat fodder on the 2 spots on the right side, the free space below your hero can only be infiltrated by tentacles, the ultimate evil can not reach you...recommended team is: illusionist with bow, monk with bow, and the champion
best skill setup in my opinion: 1 money, 1 slow-mo, 1 critical increase, 1 speed level, 1 evasion level, 3 battery level, remaining points all into damage skill
Final setup for your ball: Dissector on rear of ball, 3 EMP guns, (3-4 Extra Stabilizers (4 if your not using gun booster)) and the guidance ball hull beats entire game by level 14, no need to repeat levels, you will like to use the shotgun until you get your first EMP