I mean it's seriously unstable.

I never had a problem with any of Majesty 2 until this expansion.
In particular, when a boss on the mission Dwarven Gratitude gets to a certain point it crashes. Since there's no cheat to instantly kill the boss, I have no idea what to do.

Sadly, they never fixed the crashing issues of Monster Kingdom.

I have completed it, but it's been a long time, and many saves where made to get along the crashing. Which mission was Dwarven Gratitude again?

Dwarven Gratitude was the one with the Sacred Valley. It crashed in the majority of missions after that.

I honestly cant remember it crashing with me.