Galio, Durand's Materpiece

When another creature you control attacks or
blocks: Galio, Durand's Materpiece has Flash.
Whenever a sorcery or instant spell is cast,
put a Petricite counter in this card.
Galio, Durand's Materpiece has Hexproof as
long as he has Petricite counter.
Remove 2 Petricite counters: counter target spell.