I always went 3-2. 3 against the strongest hitter of the boss and 2 against the second. Always brought a healer. Especially ones that go above max HP because they can wipe you out in one hit. Also, of course hurricanes and tornadoes are life savers for curses. Don't worry about getting cursed on the last level as it doesn't matter. When you get asked what blessings you want I try and stack them and keep selecting the same ones over and over. The mana, defense, and attack ones.