Appa, Steadfast Guardian + Cloud Key + Felidar Guardian + Grand Arbiter Augustin IV

Appa, Steadfast Guardian

Cloud Key

Felidar Guardian

Grand Arbiter Augustin IV

How it works

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