Time Sieve + Encroaching Mycosynth + Rionya, Fire Dancer + Phylath, World Sculptor

Time Sieve

Encroaching Mycosynth

Rionya, Fire Dancer

Phylath, World Sculptor

How it works

1. At the beginning of your combat phase, Rionya triggers, creating at least one token copy of Phylath with haste.
2. Put the Phylath token into your graveyard due to the legend rule.
3. The Phylath token enters-the-battlefield ability triggers, creating at least five 0/1 Plant creature tokens.
4. Activate Time Sieve by tapping it and sacrificing the Plant tokens, causing you to take an extra turn after this one.
5. Repeat each turn.

This ingenious loop lets you seize infinite turns by turning your entire battlefield into a mechanical orchestra, fueled entirely by Phylath, World Sculptor and Rionya, Fire Dancer. Because Encroaching Mycosynth makes every nonland permanent you control an artifact, the swarm of Plant tokens created by Phylath's entry (or by making a token copy of Phylath itself) instantly qualify as the heavy payment required for Time Sieve's ability. You simply use Rionya's combat trigger to continuously clone Phylath, harvest the resulting Plant tokens, and feed them directly into Time Sieve to lock down the game with endless consecutive turns.