Great suggestions, folks, thanks
So far I'm strongly leaning toward the skill-based names, with some added fluff to round the title out so it's not just one word. Something like "Excelsiorian Adept", "Excelsiorian Elder", etc. Or perhaps "Excelsior Adept" though that tweaks my OCD since it's not really grammatically correct.
Possibly something along the lines of "Adept of Excelsior". Thoughts?
Oh, also. Eventually there will be a gump that will let you browse all your unlocked titles and select which one to display. That was already part of Elysium & Touria's coding needs and it'll work handily for other types of special titles, like these.