Movie that had thieves trying to get a orb through booby traps in a castle and the thief that touched it half his face changed and at the end he was sitting on a throne

Treasure of the Four Crowns (1983)
From Wikipedia:
Striker retrieves the gems from the two magical crowns, and the magic makes his head literally spin. His face becomes half deformed... Striker shoots fire from his fingers, melting the henchmen, their weapons, and Jonas.


https://en.wikipedia.org/wiki/Treasure_of_the_Four_Crowns

This was part of the second wave of 3D movies, nearly three decades after the first attempt to bring 3D to movie audiences. Today's third wave seems to be wearing out its welcome.