I think The Omen 2 is a pretty decent flick even though it doesnt add much to the lore of Damien besides him being a preteen/teen at military school
Exorcist II in a way was just weird with African nonsense thrown in
I agree with tou. The Omen 2 is a story with a decent filmwork.
The Exorcist 2 is a feverdream of radical visuals and very little sense.
It's a been a long time since I've seen E2, I can't remember how "weird" it is. But I do think O2 is a very underrated film in my opinion but I don't find it "weird" per se. I liked both movies but I think I like O2 more.
As far as which movie is weirder, I gotta go with E2. But I'd have to watch it again to say for sure.