Appa, Steadfast Guardian + Wispweaver Angel + The Wind Crystal + Gathering Stone

How it works

1. Cast Appa either from your hand or from the command zone by paying plus commander tax, if applicable.
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.