The Siege Perilous

Whenever a creature you control whose name
hasn't been noted for The Siege Perilous attacks,
note its name for The Siege Perilous and put a
quest counter on The Siege Perilous.
As long as The Siege Perilous has twelve or more
quest counters on it, equipped creature gets
+6/+6 and has vigilance, lifelink, and indestructible.
Equip {w}