Appa, Steadfast Guardian + Restoration Angel + Cloud Key + Stormscape Familiar

Appa, Steadfast Guardian

Restoration Angel

Cloud Key

Stormscape Familiar

How it works

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