Cast Channel by paying {G}{G}.
Activate Phyrexian Altar by sacrificing Blex, adding {U}.
When Blex dies, it and Fool's Demise's first and second abilities trigger.
Resolve the Blex trigger, causing you to gain 4 life.
Resolve the first Fool's Demise trigger, returning Blex from your graveyard to the battlefield.
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 Blex.
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

Blex, Vexing Pest // Search for Blex

Combos with "Blex, Vexing Pest // Search for Blex"