Dyadrine, Synthesis Amalgam + Crystalline Crawler + Resourceful Defense + Myth Unbound + Phyrexian Altar

Dyadrine, Synthesis Amalgam

Crystalline Crawler

Resourceful Defense

Myth Unbound

Phyrexian Altar

How it works

1. Cast Dyadrine from the command zone by paying plus commander tax, if applicable, reduced by 1 for each time you've cast Dyadrine this game from the command zone due to Myth Unbound. Dyadrine will enter the battlefield with a +1/+1 counter on it for each mana spent to cast it.
2. Activate Phyrexian Altar by sacrificing Dyadrine, adding 1.
3. Choose to return Dyadrine from the battlefield to the command zone.
4. When Dyadrine dies, Resourceful Defense triggers, putting a number of +1/+1 counters on Crystalline Crawler equal to the number Dyadrine had as it died.
5. Activate Crystalline Crawler by removing all +1/+1 counters placed on it in step 4, adding and then 1 for each remaining counter.
6. Repeat.

This clever loop turns your commander, Dyadrine, Synthesis Amalgam, into a self-sustaining engine by repeatedly casting it from the command zone at a reduced cost thanks to Myth Unbound. When you sacrifice Dyadrine to Phyrexian Altar, Resourceful Defense swoops in to salvage its massive pile of +1/+1 counters, safely depositing them onto Crystalline Crawler instead of letting them vanish. Crystalline Crawler then cashes in those very counters for the exact colors of mana you need to recast Dyadrine and repeat the entire cycle.