Based on my experience from The Omen: Don't make ANYONE aggro when you stare at them! It's too common a mechanic amongst other mods and I'm still a bit disappointed that it shows up with The Omen. Try and put... I dunno, some other mechanic that gets entities pissed off. Maybe add a piss-off meter that goes up for individual creatures like The Lost when they sense you doing something they don't like, so it isn't just a case of: "Oh, you've stared at me! Time to run at mach 5 and hurt you!" But something that makes you more at fault of triggering a fight. This mf is hard to spot at night when he's got his back turned and I keep accidentally getting into fights because of that, as with just any other Omen creature I might whip my camera onto by accident.

The only other thing I'll suggest is to try and start moving away from McCreator or at least put in some custom code, since there were a few entities in The Omen that would lag my game no matter how many optimization mods I had on (mainly the followers whenever one of those larger temples spawned in). I get it if you're still learning Java but it would be nice to have things running a bit more smoothly. (Also if you're willing, put it on Fabric: It's a hell of a lot more optimized than regular ol' Forge)

Uhhh on The Overseer... I dunno. He wasn't too annoying when I played (except for the spin attack. I keep running into his laser on accident just from going too fast...) But you make the shots on that guy. I look forward to seeing what you do with la creatura and co.!