Wasn't Lilcarla also the earlier beast tamer/hero? I have a fuzzy memory from the earlier chapters.
All right, coming from a binge read:
According to the elves and Pappy, Lilcarla was a monster tamer. However from Noa's recollection of human history, she was known as the Demon Lord. So he put two and two together and figured she was a monster tamer that got mistaken for the Demon Lord, which foreshadowed his fate. The recent record from the pope battle and Lilcarla's possession of Ruri, her servant/descendant, seem to confirm that she was and may still be the Demon Lord.
That's the situation so far. Noa hasn't evolved his class yet, and he's worried the next stage for him is Demon lord.