Zisanu, Shield Wielder

Vigilance, hexproof
Whenever a creature with defender enters the
battlefield under your control, put a +1/+1
counter on Zisanu, then you may draw a card.
{x}: The next time target creature, player, or
planeswalker would be dealt damage this turn,
prevent up to twice X of that damage. Zisanu
gets -X/-X until end of turn.