Eternal Hero of Elona

I've been adding titles to my HoM, and I noticed that I can't add Eternal Hero of Elona, even though I have beaten all missions (and bonuses) in NM and HM. I thought you just get it for beating Nightfall, is there something else I have to do?

You *should* be able to add Eternal Hero to your HoM if you've finished the Abaddon's Gate mission, yes.

Just to check though (and rule out the usual suspects):

Are you on the correct character when you look to add it to your HoM?
Are you in Account-wide view or personal view (can't recall if this makes a difference for toon-based titles, tbh).
Have you checked the list of available titles already added to your HoM to make certain it's not already on there somewhere?

Make sure you've done all the ones on newbie island too, aswell as the ones from alternate story paths in Nightfall. Those are the other usual suspects for people with this problem.

EDIT: Sorry thinking of the wrong title. This is often the case for Protector and Guardian though.

also commonly overlooked is did you do both sets of missions when you choose to go with Master of whispers or Margrid and also the split where you choose to listen to Koss or Melonni

Unless I'm mistaken, Hero of Elona should only be completing Abaddon's Gate. If you've done so but don't see the option, try checking the HoM reward calculator site; you may have added it and forgotten.

Yup, Hero only needs the last mission completed, only protector and guardian need everything.
What others said, check it's not in account view etc.