Toph, Greatest Earthbender + Power Depot + Crystalline Crawler + Altar of Dementia + The Earth Crystal
Toph, Greatest Earthbender
Power Depot
Crystalline Crawler
Altar of Dementia
The Earth Crystal
Infinite artifact ETBInfinite artifact LTBInfinite artifact sacrifice triggersInfinite +1/+1 counters on creatures you controlInfinite creature ETBInfinite creature LTBInfinite colored manaInfinite death triggersInfinite landfall triggersInfinite millInfinite creature sacrifice triggersInfinite self-mill
How it works
Play Power Depot, which will enter with a +1/+1 counter on it due to its modular ability
Cast Toph either from your hand or from the command zone by paying 2 plus commander tax if applicable.
When Toph enters, it triggers, earthbending Power Depot and putting a number of +1/+1 counters on Power Depot equal to the mana spent to cast Toph, increased by The Earth Crystal.
Activate Altar of Dementia by sacrificing Power Depot.
When Power Depot dies, its modular ability and Toph trigger.
Resolve the modular trigger, putting the +1/+1 counters that were on Power Depot onto Crystalline Crawler, increased by The Earth Crystal.
Resolve the Toph trigger, returning Power Depot from your graveyard to the battlefield tapped. Power Depot will enter with a +1/+1 counter on it due to its modular ability
Resolve the Altar of Dementia ability.
Activate Altar of Dementia by sacrificing Toph. Choose to return Toph from your graveyard to the command zone.
Activate Crystalline Crawler by removing a +1/+1 counter from it, adding R/G.
Repeat step 10 until you have enough mana to cast Toph.