So I checked out Ketheric Torm after visiting Nightsong.
This scroll is capable of bugging the game, at the moment when the castscene should be played, nothing happens, but the petrification passes and you can continue to beat them.
As a result, Ketheric Torm continues to fight with 0 HP, and it is impossible to kill him on the roof of the towers, so as not to crash the game
You only have to lower his HP to 40 up there for another cutscene, since you have fight him again 2 more times.
