User blog comment:Pualover/Overlord Power Level/@comment-96.227.219.59-20150928193147/@comment-103.14.61.135-20151002191516

^Who else could it be?

Spinel/Lastborn of Pleiades/Rubedo/Area Guardian of Cherry Blossom Sanctuary.

All of them reside on the 8th floor. Heck I wouldn't be suprised if they're all the same person.

Pick one who is level 100. There really isn't any other choice. It is proven that there is only one another level 100 NPC in Nazarick based from the new official artwork.