Apparently I've been teleported here to stop some one named Tartarus from getting "The Index", and after entering his chamber was I in for a world of hurt! From atop his god shield platform he summoned exploding fire wolves and worse, insta-kill bombs that would drop from the ceiling! There was no evading the death blast, instead I needed to shoot all of them before they hit the floor - which still somehow ignited all the oil spills across the surface.
They happen to look like sea mines...
With enough damage done to the floor we both fell to the lower level where Tartarus summoned an easily beatable flame elemental. His meteor storm spell was quite annoying though, but thankfully nullified by turning off a submerged gas valve nearby. Annoyed at this Tartarus then decided I'd freeze instead of burn, coating the entire area with ice and summoning ice elementals who when killed shattered into smaller and smaller versions of themselves. It took me some time to realize that they would also "join" back together. While the combat wasn't difficult, ensuring that all the ice pieces from the defeated enemies stayed apart was quite tricky.
Electrifying a water skeleton makes it weaker?
A couple of moving platforms later and I was now in a chamber with elemental skeletons while Tartarus ran away. This was really annoying as the only way to damage them was to lure them to the corresponding opposite element, and since they were aware enough to stay away from said locations I was purely relying on knock backs to get the job done. Very tedious and frustrating. My reward for getting past that chamber were twin energy swords from Halo. Huh!?
Hrm, this feels very cross-overish!