Requires

Steps

1. Cast Changeling Outcast by paying .
2. When Changeling Outcast enters the battlefield, Cloudstone Curio and Bladewing's Thrall trigger.
3. Resolve the Cloudstone Curio trigger, choosing to return nothing to your hand.
4. Resolve the Bladewing's Thrall trigger, returning it from your graveyard to the battlefield.
5. When Bladewing's Thrall enters the battlefield, Cloudstone Curio triggers, returning Changeling Outcast from the battlefield to your hand.
6. Activate Phyrexian Altar by sacrificing Bladewing's Thrall, adding .
7. Repeat.

Results