Inner Demon

Hexproof, trample, haste.
As an additional cost to cast this card, pay 2 life
for every berserker under your control. This
card gains +X/+X counters, where X is the total
mana paid and the total life paid to cast it.
Thirst for Battle - If this card deal combat damage
to a creature or player, untap all berserkers you control, there is an additional combat phase
this turn.