So, a few notes:

Reyaryn Cious is from the base game, in the Cravers questline.

Fluffpetal Gurk'Zvar is from the Vaulters expansion, and is acquired by defeating all pirate dens in the galaxy, triggering a competitive quest to defeat their leader.

I don't think Esseb Veltaros is a Concrete Endless. They were posing as a Vodyani initially, and the DotE and EL Archivists were Haunts, which seem to be Virtuals. So Virtual seems much more likely to me. If Veltaros is indeed a Virtual, though, then it is strange that Amplitude didn't give them the Virtual skills...

I have no idea about Five or Ahririnn Turlemmoz.