Cast Channel by paying {G}{G}.
Activate Phyrexian Altar by sacrificing Saruli Gatekeepers, adding {U}.
When Saruli Gatekeepers dies, Fool's Demise's first and second abilities trigger.
Resolve the first Fool's Demise trigger, returning Saruli Gatekeepers from your graveyard to the battlefield.
When Saruli Gatekeepers enters the battlefield, it triggers, causing you to gain 7 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 Saruli Gatekeepers.
Repeat from step 2.

Infinite colorless mana

Infinite death triggers

Infinite ETB

Infinite lifegain

Infinite lifegain triggers

Infinite LTB

Infinite sacrifice triggers

Infinite storm count

Fool's Demise

Channel

Phyrexian Altar

Saruli Gatekeepers

Combos with "Saruli Gatekeepers"