Golgari Thug + Phyrexian Altar + Dross Harvester + Gwenom, Remorseless

Golgari Thug

Phyrexian Altar

Dross Harvester

Gwenom, Remorseless

How it works

1. Activate Phyrexian Altar by sacrificing Golgari Thug.
2. When Golgari Thug dies, it and Dross Harvester trigger.
3. Resolve the Golgari Thug trigger, putting it from your graveyard onto the top of your library.
4. Resolve the Dross Harvester trigger, causing you to gain 2 life.
5. Cast Golgari Thug from the top of your library by paying 2 life.
6. Repeat.

This clever loop uses Phyrexian Altar to churn through your deck by repeatedly sacrificing Golgari Thug, generating infinite colored mana and death triggers along the way. When Golgari Thug hits the graveyard, its triggered ability puts itself right back on top of your library, and Dross Harvester offsets the life you'd normally need to spend. That life management is crucial because Gwenom, Remorseless lets you cast that Golgari Thug straight from the top of your library by paying life equal to its mana value instead of its mana cost, sealing an airtight perpetual engine.