Kamaljiori

Kamaljiori is the androsphinx mate of Osysa who resides in a forgotten temple of Ioun, goddess of knowledge. According to Osysa, he had knowledge of the lost Vestiges of the Divergence, and, when Vox Machina passed his trial, revealed that he had the Mythcarver in his possession.

The Lair
Vox Machina, in their quest to find the Vestiges of the Divergence to help end the threat of the Chroma Conclave, traveled to the the Frostweald just north of the Stormcrest Mountains on Osysa's promise that her mate would be able to help the party further.

After activating an obelisk that appeared to be dedicated to Ioun, the party eventually made their way to the base of the mountain, coming to a triangularly cut cave.

Within was a pool, with an underwater tunnel that appeared to connect to another. Grog and Keyleth went scouting ahead, but strange red tendrils extended from the walls of the tunnel and paralyzed Grog. After getting him back out, Keyleth created a tunnel of air through the passageway, and the group made it through the water trial unharmed.

The Nameless Sphinx
The sphinx demanded Vox Machina speak his name. When they failed to do so, he attacked, activating a series of extraplanar gateways scattered around his lair. After several devastating rounds of combat, Vex secured a rope and jumped into a seemingly bottomless well, a gateway to the Plane of Water. She emerged hurriedly and shouted out two letters, presumably part of the sphinx's name.

The rest of Vox Machina followed suit, and in short order, all the gateways had been probed save the gateway to the Plane of Air. Grog jumped in without a rope, discovered the letters, and began drifting away from the gate. When Vax dived in after him with a rope, Grog instead attached his Chain of Returning to Craven Edge and threw it through the gate, skewering Pike accidentally.

When all the letters had been discovered, Percy began spouting out any combination he could think of, finally hitting upon "Kamaljiori". Upon hearing his name, the sphinx immediately ceased combat, deactivating the gates and returning to his dais. He shared the locations of the Vestiges he knew about, and then presented the Mythcarver to Vox Machina, a longsword that once belonged to the legendary bard known as the White Duke.

When Kamaljiori had said all he was willing to say, he summoned a sandstorm and teleported the group back out into the Frostweald, sealing the entrance behind them.