Castle Black

{t}:Add {b}{b}, {b}{s}, or {s}{s} to your mana
pool.
Oath of Abstinence—Creatures you control have
shroud.
Take The Black—If a creature were to die, you may
pay {s}{s}{s}{s} and tap Castle Black to exile that
creature instead. You may return that creature to
the battlefield by paying its mana cost in either black
or snow mana. Creatures returned to the battlefield
by Castle Black have defender.