Mortuary + Narcomoeba + Sanguine Spy + Mana Echoes

Mortuary

Narcomoeba

Sanguine Spy

Mana Echoes

How it works

1. Activate Sanguine Spy by paying 1 and sacrificing Narcomoeba.
2. When Narcomoeba dies, Mortuary triggers, putting Narcomoeba on top of your library from your graveyard.
3. Resolve the Sanguine Spy ability, causing you to put Narcomoeba into your graveyard from the top of your library.
4. Narcomoeba triggers, returning itself to the battlefield from your graveyard.
5. When Narcomoeba enters the battlefield, Mana Echoes triggers, adding at least C.
6. Repeat.
7. If you control at least one other Illusion, this combo will net infinite colorless mana.

This intricate loop turns a simple sacrifice into a self-sustaining engine by manipulating your library and graveyard in a continuous cycle. Sanguine Spy acts as the sacrifice outlet that feeds the engine, allowing you to pay mana to surveil Narcomoeba back into the graveyard, which in turn triggers Narcomoeba's own ability to return straight to the battlefield. Meanwhile, Mortuary ensures Narcomoeba never stays lost by quietly placing it back on top of your library whenever it leaves the battlefield for the graveyard. As Narcomoeba repeatedly re-enters, Mana Echoes amplifies the cycle by generating colorless mana with each arrival, provided you have enough shared creature types to net a profit.