Chapter 10 Mission 2
Enemy Hero: Salamander King
Boss Element: Void Element.
Enemy Level: 720
Energy Cost: 185
- 0% Mastery: 940 XP / 8600 Gold
- 100% Mastery: 1128 XP / 10320 Gold
- 200% Mastery: 1316 XP / 12040 Gold
- 300% Mastery: 1504 XP / 13760 Gold
Ice Blaster II takes care of him and every single one of his units.
If you don't have enough attack power to kill him with IB2 then Dragon Warriors work fine as well.