boss 33 - call of house hardabar - the great drake (the hive) 

Call of House Hardabar (Grimrock 2 MOD). Difficulty: Hard.
Download: www.nexusmods.com/legendofgrimrock2/mods/167
Special attack of "dragon riffle" is good here.
---------------------------------------------------------------------
It is essential to install the 4GB Patch to prevent the game from crashing (this happens in large mods for technical optimisation reasons):
www.ntcore.com/4gb-patch/
Download the program, run it, then it will ask for a path, then choose the path where the grimrock 2 executable is: "grimrock2.exe".