Unstable Shapeshifter + Chainer, Nightmare Adept + Infinite Reflection + Liliana, Dreadhorde General

Unstable Shapeshifter

Chainer, Nightmare Adept

Infinite Reflection

Liliana, Dreadhorde General

How it works

1. Discard a card to activate Unstable Shapeshifter's ability from Chainer, allowing you to cast a creature spell from your graveyard this turn.
2. Cast a creature spell from your graveyard by paying 0.
3. Due to Infinite Reflection, that creature enters the battlefield as a copy of Unstable Shifter copying Chainer.
4. Put that creature in the graveyard due to the legend rule.
5. That creature entering the battlefield and dying triggers its own Chainer ability, Unstable Shapeshifter's Chainer ability, and Unstable Shapeshifter's original ability.
6. Resolve the two Chainer triggers, failing to grant anything haste.
7. Resolve the Liliana trigger, drawing a card.
8. Resolve the Unstable Shapeshifter ability, causing it to become a new copy of Chainer that has not yet activated its ability this turn.
9. Repeat.