I believe the 3rd's Frieren now? Doesn't she have the medallion as well?
It's Frieren, I was just re-reading some chapters and at ch. 45 during the first exam the two first class mages who oversee the exams start talking about Frieren's identity and one of them mentions how she was carrying the holy emblem (the old necklace) and the other mage then calls her "The last great mage”, so apparently that emblem really is a proof of a great mage, although I wonder if Frieren even knows that.
I betcha she was told so, but didn't care / bother to remember :))))
who were the 3 great mages? serie, minus, and flamme? or is it frieren?