Appa, Steadfast Guardian + Ballad of the Black Flag + Aang, the Last Airbender

Appa, Steadfast Guardian

Ballad of the Black Flag

Aang, the Last Airbender

How it works

1. Cast Appa by paying .
2. When Appa enters, it triggers, airbending Aang.
3. Cast Aang from exile by paying 0.
4. Appa triggers, creating a 1/1 Ally creature token.
5. When Aang enters, it triggers, airbending Appa.
6. Cast Appa from exile by paying 0.
7. Repeat from step 2.

This infinite loop relies on the cost-reduction power of Ballad of the Black Flag's fourth chapter, which makes historic spells cost {2} less to cast. Because Appa, Steadfast Guardian and Aang, the Last Airbender are both legendary, they count as historic spells, reducing their exile-casting cost of {2} down to a completely free {0}. As you continually cast each Avatar from exile to trigger the other's airbend ability, Appa's secondary triggered ability turns every single cycle into a brand new 1/1 white Ally creature token.