Hotis the Rakshasa

Hunted and killed by Vox Machina in Vasselheim during the Trial of the Take min-arcs.

If / when he comes back, I might transfer some info from the board I made that ep, which is in a different filing system currently.

Resurrected, which is apparently just a thing fiends can do, and came to take revenge on Vax.

He impersonated Shaun Gilmore for an unknown period of time, before luring Vax out on to a balcony and attempting to assassinate him.

At the same time as this attempt, assassins hired by Hotis, from, WHO COULD HAVE GUESSED IT, The Clasp , attempt to assassinate the rest of Vox.

Vox fights em all off, and kills Hotis again. It promised to be back.

Allura Vysoren indicated that it would likely be somewhere between weeks and months before he would be able to return.

We have no idea how long or to what degree this Rakshasa impersonated Gilmore. It could have been as short of a time as that single interaction, or it could have been for a LONG while.
The only caveat to this, is that ostensibly real Gilmore was still in Whitestone after they killed the Rakshasa, and didn't seem surprised to see the party. So this means that the Gilmore that Vox told to go to Whitestone as well as the one that they met when they first arrived were both likely the real Gilmore.