Appa, Steadfast Guardian + Umori, the Collector + Wispweaver Angel + Pearl Medallion

Appa, Steadfast Guardian

Umori, the Collector

Wispweaver Angel

Pearl Medallion

How it works

1. Cast Appa by paying
2. When Appa enters, its first ability triggers, exiling Wispweaver Angel with the ability to cast it later from exile.
3. Cast Wispweaver Angel from exile by paying 0.
4. Appa's second ability triggers, creating a 1/1 Ally creature token
5. When Wispweaver Angel enters, it triggers, blinking Appa.
6. Repeat from step 2.