Secret Shadow

When Secret Shadow, Surveil 2 (Look at the top 2
cards of your library, then put any number of them
into your graveyard and the rest on top of your library
in any order.)
Mill a Card {1}{u}{b}: Regenerate Secret Shadow
Transmute{2}{u/b}{u/b}
Cipher (Then you may exile this spell card encoded
on a creature you control. Whenever that creature
deals combat damage to a player, its controller may
cast a copy of the encoded card without paying its
mana cost.)