Time Sieve + Encroaching Mycosynth + Bishop of Wings + Maskwood Nexus

Time Sieve

Encroaching Mycosynth

Bishop of Wings

Maskwood Nexus

How it works

1. Activate Time Sieve by tapping it and sacrificing five other creatures.
2. When the creatures die as Angels due to Maskwood Nexus, Bishop of Wings' second ability triggers five times.
3. Resolve the first trigger, causing you to create a 1/1 Spirit creature token.
4. When the Spirit enters the battlefield as an Angel due to Maskwood Nexus, Bishop of Wings' first ability triggers, causing you to gain 4 life.
5. Repeat from step 3 for each remaining trigger.
6. Resolve the Time Sieve ability from step 1, causing you to take an extra turn after this one.
7. Repeat each turn.

This clever loop relies on Encroaching Mycosynth and Maskwood Nexus working in tandem to turn your entire board into an army of artifacts that are simultaneously every creature type, including Angels. With this type-shifting foundation in place, sacrificing five creatures to Time Sieve triggers Bishop of Wings five times as those creatures die. Those deaths yield five 1/1 Spirit tokens which, thanks to the Nexus, enter as Angels to trigger the Bishop's lifegain ability and replace your sacrificed fodder, leaving you with enough new permanents to continually pay Time Sieve's cost and lock down infinite extra turns.