In your opinion, what normal monsters are the hardest even if you are at high levels?

the Crysknight(rare) in Geruvegan was annoying, not hard, but he has high HP and can hit.

I guess I can say the Entities were fearsome, they slowly followed you.
Hmm, there was an enemy, who wasn't a malbororo, that herald status ailments on me... I forgot what name it was, I needed vaccines. It was at giruvegan, in the watersteppes.