Starving Revenant and Wizard Class trigger for each card drawn.
Resolve all Starving Revenant triggers, causing you to gain 1 life and target opponent to lose 1 life for each trigger.
Resolve the first Wizard Class trigger, putting a +1/+1 counter on Fetid Gargantua.
Fetid Gargantua triggers, causing you to draw two cards and lose 2 life.
Repeat from step 2.
This engine turns a single card draw into a self-sustaining loop by leveraging Wizard Class at level 3, which places a +1/+1 counter on Fetid Gargantua whenever you draw. That counter triggers Fetid Gargantua to draw two cards, which in turn fuels Wizard Class all over again while Starving Revenant sits on the board to bleed out your opponent and cushion your life total every single time a card changes hands.