Rost, the Walking Glacier

Entomb - The ability of a unit with Entomb will activate when it dies. This combines well with effects that sacrifice units as a cost.

Warp - You can see cards with Warp when they are on top of your deck, and you can play them as if they were in your hand.

Shift - When played, you may instead pay the Shift cost. Shifted units can't attack, block, or be selected until they emerge.

Emerge - After three turns, Shifted units emerge and get Unblockable that turn.