Goranthir was the firstborn son of Morgiah from a forum RP. I'm not sure who was responsible for the character, but some devs have been at least peripherally involved with Loranna's.
More info on the character here: http://lorannarp.pbworks.com/w/page/19009003/Character%20Sheet%20-%20Goranthir
He's a dunmer/altmer hybrid, notably looking like an altmer with red eyes.

Enthir is a bosmer in the engine, but identifies himself as altmer in dialogue, and does have red eyes. The names are also remarkably similar.
If true (and the Nightingales is to be believed), this would make him not just Karliah's friend, but also second cousin.