Naiser Zo'Rais, Clan Leader

Flying, Changeling (This card is every creature
type at all times.)
When Naiser Zo'Rais, Clan Leader attacks, each
opponent loses 1 life and you gain that much life.
{2}{u}{b},{t}: Look at the top card of target
opponent's library. You may exile this card face
down. For as long as that card remains exiled,
you may look at it and you may spend mana
as though it were mana of any type to cast it.