Sif, Guardian of The Grave

Partner with, "Artorias, The Abysswalker"
(When this creature enters the battlefield, target
player may put "Artorias, The Abysswalker"
from their deck into their hand then shuffle.)
Menace, First Strike, Vigilance
While this card is on the field cards cost {0} Mana
to Equip to Creature Cards.