Activate Phyrexian Altar by sacrificing Su-Chi, adding .
Su-Chi dies, triggering itself and Fool's Demise first and second abilities.
Resolve the Su-Chi trigger, adding CCCC.
Resolve the second Fool's Demise trigger, returning it from your graveyard to your hand.
Resolve the first Fool's Demise trigger, returning Su-Chi from your graveyard to the battlefield.
Cast Fool's Demise by paying 4, attaching it to Su-Chi.
Repeat.
This clever loop transforms Su-Chi into an endless fountain of resources by leveraging a classic recycling mechanism. When you sacrifice Su-Chi to Phyrexian Altar, its death triggers both its own mana-producing ability and Fool's Demise's resurrection effect, which simultaneously returns the Aura to your hand and the construct back to the battlefield. Because Su-Chi generates four color-blind mana when it bites the dust, you easily profit enough mana to recast Fool's Demise and repeat the entire cycle. The result is an unstoppable engine that generates infinite storm count, death triggers, and sacrifice fodder.