Shabraz and Wizard Class trigger for each card drawn.
Resolve all Shabraz triggers, causing you to gain 1 life and put a +1/+1 counter on Shabraz 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 mesmerizing loop is fueled by a clever self-sustaining cycle of card draw and counter placement. Once Wizard Class reaches level 3, its ability triggers whenever you draw a card to place a +1/+1 counter on Fetid Gargantua, which in turn triggers the Gargantua's own ability to draw two more cards and lose a bit of life. Meanwhile, Shabraz, the Skyshark rides the wave of all that drawing by continuously stacking up +1/+1 counters and life gain, perfectly supported by Wizard Class's static hand size exemption so you never have to discard your expanding hand.