hearty coyote
(I'll admit, I can't remember if this is correct, I don't have the best memory in general.) I don't want to tag everything as spoilers, so don't read ahead for any players that want to figure out the Omed fight for themselves.
As much fun as having a secret superboss in the game is, having the fight against Omed be required to clear the area is not the best idea. If it's required, then No Stone Unturned requires it. This is including the knowledge of his weaker form by playing the demo. There's already a lot of confusion from players who don't realize the hint within his name or the steam achievement itself, and so you'll likely hear about it for years to come. And there are players who get to that point in the game and ask for help. Some groan at the idea of doing a demo playthrough, just to weaken him and nothing more, not wanting to redo all of that adventuring.
Maybe the area should automatically clear when first entered. Then pushing the button can summon Omed any number of times. This would make him optional for people who want to fight him in either form, and give an option to players who just want to mess around and see how fast or how many times they can kill him.
...Again, I can't actually remember if he's required to kill or be killed by to clear the area 😅
hardy ether
dusky flax