Pawn of Ulamog + Phyrexian Altar + Reassembling Skeleton

B identity

Commander legal

The 3 combo pieces

How to execute it

  1. Activate Phyrexian Altar by sacrificing Reassembling Skeleton, adding {B}
  2. Pawn of Ulamog triggers, creating a 0/1 Eldrazi Spawn creature token with "Sacrifice this creature: add {C}"
  3. Activate the Eldrazi Spawn by sacrificing it, adding {C}.
  4. Activate Reassembling Skeleton by paying {1}{B}, returning it from your graveyard to the battlefield tapped.
  5. Repeat.

What the combo produces