Cast Jirina from the command zone by paying 1 plus commander tax, if applicable.
When Jirina enters the battlefield, it and Mana Echoes trigger.
Resolve the Jirina trigger, creating a 1/1 Human Soldier creature token for each time you've cast Jirina from the command zone this game.
When the Human Soldiers enter the battlefield, Mana Echoes triggers that many times.
Resolve the first Mana Echoes trigger, adding C for each Human and Soldier you control.
Repeat step 5 for each remaining Mana Echoes trigger created in steps 2 and 4.
Activate Shilgengar twice by sacrificing Jirina and a Human Soldier.
Choose to return Jirina to the command zone from your graveyard.
When Jirina and the Human Soldier die, Pitiless Plunderer triggers twice, creating two Treasure tokens.
Holding priority, if you control a Human Soldier, activate Shilgengar by sacrificing a Human Soldier.
If you sacrificed a Human Soldier this way, Pitiless Plunderer triggers, creating a Treasure token.
Resolve the Shilgengar abilities from steps 7 and 10
Activate up to three Treasures by tapping and sacrificing them, adding any combination of , and .
Repeat.
This delightful engine relies on a self-sustaining loop of sacrifice and resurrection to repeatedly churn through Jirina Kudro's command zone tax, generating an overwhelming surplus of resources along the way. Every time Jirina enters the battlefield, she brings a growing army of Human Soldiers whose presence supercharges Mana Echoes, instantly flooding your pool with colorless mana whenever they or subsequent tokens arrive. Meanwhile, Pitiless Plunderer watches the carnage, turning every sacrifice into a steady stream of Treasure tokens to fix your colors while Shilgengar, Sire of Famine provides the necessary outlet to grind your creatures down into Blood tokens. Ultimately, Shilgengar's mass-reanimation ability allows you to pull your entire team right back out of the graveyard to repeat the cycle infinitely.