Appa, Steadfast Guardian + Semblance Anvil + Felidar Guardian

Appa, Steadfast Guardian

Semblance Anvil

Felidar Guardian

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 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.

This ingenious loop revolves around Semblance Anvil, which you use to imprint a creature card from your hand, reducing the cost of all creature spells you cast by {2}. Because Appa, Steadfast Guardian allows you to cast exiled permanents for {2}, your imprinted Semblance Anvil discounts Felidar Guardian's recast cost down to exactly {0}. When Appa enters the battlefield, it exiles Felidar Guardian, letting you cast it for free; that free cast triggers Appa to mint a 1/1 Ally creature token, and Felidar Guardian's entry blink resets Appa to repeat the cycle indefinitely.