Time Sieve + Encroaching Mycosynth + Xathrid Necromancer + Conspiracy

Time Sieve

Encroaching Mycosynth

Xathrid Necromancer

Conspiracy

How it works

1. Activate Time Sieve by tapping it and sacrificing five other creatures.
2. When the creatures die as Humans due to Conspiracy, Xathrid Necromancer triggers five times, creating five 2/2 Zombie creature tokens.
3. Resolve the Time Sieve ability, causing you to take an extra turn after this one.
4. Repeat each turn.

This intricate loop lets you bend time to your will by turning your entire battlefield into a factory for sacrificial fodder. With Conspiracy naming Humans and Encroaching Mycosynth ensuring everything you control is an artifact, every creature you own simultaneously counts as a Human artifact ready to feed Time Sieve. When you tap and sacrifice five of those creatures to Time Sieve for an extra turn, Xathrid Necromancer watches them die and instantly triggers to replace them with five new 2/2 Zombie creature tokens—which are *also* artifacts thanks to Encroaching Mycosynth. You can simply repeat this process on each of your extra turns to lock down the game with an infinite succession of them.