Stalwart Successor + Phyrexian Altar + Putrid Goblin

Stalwart Successor

Phyrexian Altar

Putrid Goblin

How it works

1. Activate Phyrexian Altar by sacrificing Putrid Goblin
2. When Putrid Goblin dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. When Putrid Goblin enters, Stalwart Successor triggers, putting a +1/+1 counter on Putrid Goblin
4. Repeat.

This clever loop turns Putrid Goblin and Phyrexian Altar into an infinite mana and sacrifice engine by exploiting how counters interact. Normally, the -1/-1 counter from persist would permanently shut down future returns, but Stalwart Successor neatly bypasses this drawback; its triggered ability places a +1/+1 counter on the Goblin the first time counters are put on it each turn, which immediately annihilates the -1/-1 counter via state-based actions. With its slate wiped clean every time it enters the battlefield, the Goblin can be sacrificed repeatedly to the Altar to fuel your victory.