Full Cortex Boss Fight - The Final Boss of Synthesis Nexus

Cavas, Forgotten Spirit

Uber Pinnacle Boss - PoEDB, Path of Exile Wiki

Not trying to stoke the flames further, but why is it okay for something like this to spawn during an Pinnacle Boss fight? : r/pathofexile

Cortex PoE Wiki

Cortex Synthesised Map PoE

The larger superficial cerebral veins, including those draining the

Path of Exile Update 2.09 Patch Notes; Released for Sentinel Update This May 18

PoEのなんかかんか: リーグ絵日記5

Offering to the Serpent (Synthesised) - Path of Exile Wiki

PoE Lake of Kalandra Skill Tree Guide – PlayerAuctions Blog