The Cruelty of Gix has exactly two lore counters on it.

At the beginning of your precombat main phase, The Cruelty of Gix triggers, putting a lore counter on it.
The Cruelty of Gix's third chapter ability triggers.
Holding priority, activate Hex Parasite by paying and removing a lore counter from The Cruelty of Gix, giving Hex Parasite +1/+0 until end of turn.
Resolve the Cruelty of Gix trigger from step 2, returning Hautli's Raptor from your graveyard to the battlefield.
Huatli's Raptor and Narci's second ability triggers.
Resolve the Narci trigger, causing each opponent to lose 5 life and you to gain 5 life.
Holding priority, activate Phyrexian Altar by sacrificing Huatli's Raptor, adding .
Resolve the Huatli's Raptor trigger, putting a lore counter on The Cruelty of Gix.
Repeat from step 2.