Combat Celebrant + Displacer Kitten + Spellbinder + Garna, the Bloodflame

Combat Celebrant

Displacer Kitten

Spellbinder

Garna, the Bloodflame

How it works

1. Declare Combat Celebrant and the creature with Spellbinder attached as attackers, choosing to exert Combat Celebrant as it attacks.
2. Combat Celebrant triggers, causing you to untap all other creatures you control and to get an additional combat phase after this one.
3. Deal combat damage using the creature that has Spellbinder attached.
4. Spellbinder triggers, causing you to copy a card exiled with it, and cast the copy without paying its mana cost.
5. Displacer Kitten triggers, blinking Combat Celebrant.
6. Resolve the spell cast in step 4.
7. Repeat each combat phase.

This loop relies on Combat Celebrant to constantly generate extra combat phases through its exertion, while the haste granted by Garna, the Bloodflame allows your attackers to dive right back into the fray without waiting. When your Spellbinder-equipped creature deals combat damage, it triggers Spellbinder to cast a free instant from exile, which in turn triggers Displacer Kitten to blink Combat Celebrant. Because blinking a creature removes its exertion status, Combat Celebrant is instantly refreshed and ready to be exerted again in the very next combat phase, fueling an endless chain of attacks and free spell casts.