Phyrexian Altar + Undying Malice + Repository Skaab + Necroduality

Phyrexian Altar

Undying Malice

Repository Skaab

Necroduality

How it works

1. Cast Undying Malice by paying , targeting Repository Skaab.
2. Activate Phyrexian Altar by sacrificing Repository Skaab, adding .
3. When Repository Skaab dies, it triggers, returning it from your graveyard to the battlefield.
4. When Repository Skaab enters the battlefield, its exploit ability and Necroduality trigger.
5. Resolve the Necroduality trigger, creating a token copy of it.
6. When the Repository Skaab token enters the battlefield, its exploit ability triggers; choose not to sacrifice a creature.
7. Resolve the Repository Skaab trigger from step 4, sacrificing the Repository Skaab token.
8. Repository Skaab's second ability triggers, returning Undying Malice to your hand from your graveyard.
9. Repeat.

This loop is a masterclass in recursive recycling, using Necroduality to double up on every nontoken Zombie you bring to the field. By casting Undying Malice on Repository Skaab, you seed the grave with the exact spell you need to retrieve later, while Phyrexian Altar provides the mana and the sacrifice outlet to keep the cycle spinning. Every time the real Repository Skaab and its token copy enter the battlefield, the exploit mechanic triggers—allowing you to cash in the token to fish Undying Malice right back out of your graveyard and into your hand to start anew.