Zuko, Firebending Master + Aggravated Assault + Upwelling

Zuko, Firebending Master

Aggravated Assault

Upwelling

How it works

1. Declare Zuko as an attacker, triggering its ability, adding an amount of equal to the number of experience counters you have.
2. Move to your postcombat main phase. You will not lose the mana due to Upwelling.
3. Activate Aggravated Assault by paying 3, causing you to untap all creatures you control and to get an additional combat and main phase after this one.
4. Repeat.

This engine transforms Zuko, Firebending Master into a one-man mana factory during combat, rapidly accumulating experience counters as you cast spells and generating mountains of red mana when he attacks. Because Upwelling ensures that your unspent mana safely persists as steps and phases transition, you can stockpile that explosive combat-generated mana into your postcombat main phase. Once there, you pump those reserves directly into Aggravated Assault to untap your board and chain endless additional combat phases together.