Noz'Karin, Herald of the Deep

Elemental Creatures you control gain Flash and
Convoke.
Each time an elemental creature enters the battlefield, Noz'Karin gains a flood counter.
You can remove flood counters to perform one of
the following effects:
- Remove 2 counters then tap Noz'Karin, counter
target spell.
- Remove {x} counters, Destroy all non-elemental creatures other than Noz'Karin on the battlefield with
converted mana cost equal to or less than {x}.