Hogaak, Arisen Necropolis + Infested Thrinax + Altar of Dementia

Hogaak, Arisen Necropolis

Infested Thrinax

Altar of Dementia

How it works

1. Cast Infested Thrinax by paying 3.
2. When Infested Thrinax enters the battlefield, it triggers, causing you to create a number of 1/1 Saproling creature tokens when a nontoken creature you control dies.
3. Activate Altar of Dementia by sacrificing Hogaak.
4. When Hogaak dies, Infested Thrinax triggers, creating eight 1/1 Saproling creature tokens.
5. Resolve the Altar of Dementia ability, causing target player to mill cards equal to Hogaak's power.
6. Cast Hogaak from your graveyard by tapping seven Saprolings.
7. Repeat from step 3.

This delightfully morbid loop turns Altar of Dementia into a self-sustaining mill engine by using Hogaak, Arisen Necropolis as both the sacrificial ammo and the recursion piece. Because Hogaak lacks a mana cost and can be cast straight from the graveyard using delve and convoke, you can sacrifice it to the Altar to mill an opponent while the flash-enabled Infested Thrinax watches on. Infested Thrinax's triggered ability steps in the moment Hogaak hits the graveyard, translating Hogaak's massive eight power into an army of eight Saproling tokens. You then simply tap those newly minted Saprolings to pay for Hogaak's convoke cost, bringing the Avatar back from the graveyard for free to repeat the slaughter all over again.