I had a really buggy fight while doing the King's Gambit quest on Hjalmar's side (note: do the Cerys version if you don't want to miss a Place of Power). The final fight of the quest is against a druid (regular, not boss healthbar enemy). This druid cheats: He uses an area effect damage burst that bypasses Quen and takes off about 1/3 of your health (on Death March) and he activates it too quickly to dodge unless you queue a dodge before he starts the animation. He doesn't have any stagger animations and his attacks can't be parried or interrupted. Dimeritium bombs don't stop him from casting magic and he's immune to all signs other than Axii (Do dimeritium bombs do anything? I tried using them against the Djinn and they did nothing in that fight either). I beat him by stunning him with Axii, hitting him once with a strong attack and then rolling away and peppering him with crossbow bolts until my stamina regened to use axii again.

I've already beaten the game on Death March and he's got to be the toughest fight in the game; not because he's particularly tough, but because he breaks all of the rules established by the game. I'm curious as to whether anyone else had a similar experience against him, or if the fight just bugged out on me?