Time Sieve + Mycosynth Lattice + Rionya, Fire Dancer + Underworld Hermit

Time Sieve

Mycosynth Lattice

Rionya, Fire Dancer

Underworld Hermit

How it works

1. At the beginning of your combat phase, Rionya triggers, creating at least one token copy of Underworld Hermit with haste.
2. When the Underworld Hermit token enters the battlefield, it triggers, creating at least four 1/1 Squirrel creature tokens.
3. Activate Time Sieve by tapping it, sacrificing the Underworld Hermit token and the Squirrel tokens, causing you to take an extra turn after this one.
4. Repeat each turn.

This ingenious loop transforms your combat phase into an endless string of extra turns by turning the entire board into fodder for Time Sieve. The engine relies on Mycosynth Lattice to turn all your permanents—including your creatures and tokens—into artifacts, which directly satisfies the five-artifact sacrifice requirement that Time Sieve demands. Once that foundation is set, Rionya, Fire Dancer steps in at the start of combat to manufacture fresh fodder by cloning Underworld Hermit. Because Underworld Hermit enters the battlefield and floods your board with Squirrel tokens fueled by your black devotion, you instantly have enough artifacts to activate Time Sieve, take another turn, and repeat the whole spectacle indefinitely.