Melira, Sylvok Outcast + Phyrexian Altar + Heartmender

Melira, Sylvok Outcast

Phyrexian Altar

Heartmender

How it works

1. Activate Phyrexian Altar by sacrificing Heartmender.
2. When Heartmender dies, its persist ability triggers, returning it from your graveyard to the battlefield without a -1/-1 counter on it due to Melira.
3. Repeat.

This elegant loop turns a persistent automaton into an endless engine for mana and triggers by exploiting a clever rules interaction. When Heartmender goes to the graveyard, its persist ability would normally return it with a -1/-1 counter, but Melira, Sylvok Outcast steps in with her static ability to completely prevent that counter from ever being placed. This allows Heartmender to return completely clean every single time it is sacrificed to Phyrexian Altar, generating an infinite supply of colored mana alongside endless enter-the-battlefield, leave-the-battlefield, and death triggers.