Sérobsi's Signet

{1}, {t}: Add {u/b}{u/b} to your mana pool. You can only
spend this mana to cast spell that mention "Surveil"
in their text box.

{2}, {t}: Surveil 2.

{1}{u}{b}, {t}, Sacrifice Sérobsi's Signet : Put one
target creature from your cemetery to your hand.