Kumena, Head Hearld

As long as Kumena is untapped, it has:
Tap an untapped Merfolk you control: Untap target land.
Tap two untapped Merfolk you control: Kumena gains hexproof until end of turn.
Tap four untapped Merfolk you control: Draw two cards.
Tap eight untapped Merfolk you control: Put a +1/+1 counter on each Merfolk you control. They gain hexproof until end of turn.