Cast Channel by paying {G}{G}.
Activate Phyrexian Altar by sacrificing Knight of Autumn, adding {U}.
When Knight of Autumn dies, Fool's Demise's first and second abilities trigger.
Resolve the first Fool's Demise trigger, returning Knight of Autumn from your graveyard to the battlefield.
When Knight of Autumn enters the battlefield, it triggers, causing you to gain 4 life.
Resolve the second Fool's Demise trigger, returning it from your graveyard to your hand.
Activate Channel four times by paying 4 life, adding {C}{C}{C}{C}.
Cast Fool's Demise by paying {4}{U}, attaching it to Knight of Autumn.
Repeat from step 2.

Infinite death triggers

Infinite ETB

Infinite lifegain triggers

Infinite LTB

Infinite sacrifice triggers

Infinite storm count

Fool's Demise

Channel

Phyrexian Altar

Knight of Autumn

Combos with "Knight of Autumn"