Ephnel is more like a blood soulworker like those in Ruin Fortress (those don't really dress modest either except Nita)
She isn't exactly on good terms with every human in general so it makes sense she is more on friendly side with Naomin than the other soulworkers.
Maybe this helps if you didn't read it yet:
I think Naomin in the video you linked is either referring to Amad or Flamar with "him". Flamar if I remember right is the upcoming raid boss and seems to be the actual leader of firestorm battalion, because when you kill Sukkarak in Cold Rain he mentions him saying "Flamar... I'm sorry"