Earned the hard badge in 5 days, 250k squad power.
6 hero squad: 4 archers and 3 tanks (1 archer tank). Vitality is king, melee damage is useless. Magic power only as much as needed. Tanks placed near archer tank, other side of the archers. And also very slow speed, 5 to 10% to prolong fight. Tanks with hp and melee AoE weapons (first fireball and later stun). Archers with max dmg items. Keep reroling fights especially to ensure high hp critters are set up at back and if possible high dmg critters are tageted by archers at start.
Good luck!
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