All Will Be One

Whenever you put one or more counters on a permanent or player, this enchantment deals that much damage to target opponent, creature an opponent controls, or planeswalker an opponent controls.

Marath, Will of the Wild

Marath enters with a number of +1/+1 counters on it equal to the amount of mana spent to cast it.
{X}, Remove X +1/+1 counters from Marath: Choose one —
• Put X +1/+1 counters on target creature. X can't be 0.
• Marath deals X damage to any target. X can't be 0.
• Create an X/X green Elemental creature token. X can't be 0.

Idyllic Tutor

Search your library for an enchantment card, reveal it, put it into your hand, then shuffle.