Arysanzyr Deep Terror

Islandwalk (This creature can't be blocked as
long as defending player controls an island)
{2}{u}, {t}: Put a deep counter on target creature.
You get an experience counter. Then, if you have
4 or more experience counters, untap Arysanzyr.
Each creature gets -X/-X for each deep counter
on it, where X is equal to the amount of
experience counters you have.