Relentless Dead + Necroduality + Phyrexian Altar

Relentless Dead

Necroduality

Phyrexian Altar

How it works

1. Cast Relentless Dead by paying .
2. When Relentless Dead enters the battlefield, Necroduality triggers, creating a token copy of it.
3. Activate Phyrexian Altar by sacrificing the nontoken Relentless Dead, adding 1.
4. When Relentless Dead dies, its first and second abilities trigger. Choose not to pay for either.
5. Activate Phyrexian Altar by sacrificing the token Relentless Dead, adding 1.
6. When the token Relentless Dead dies, its first and second abilities trigger.
7. Resolve the first trigger, choosing not to pay.
8. Resolve the second trigger, causing you to pay 2 to return Relentless Dead from your graveyard to the battlefield.
9. Repeat from step 2.