I don’t think Jason Voorhees is a “Deadite”, but he’s essentially born from the same method that Deadites are created and shares some common traits. Such as enhanced strength and durability.

My theory is Pamela Voorhees isn’t exactly a master of the occult, but she did some -c-

-c- research beforehand. But possibly still messed up. Jason was partly revived. But still as a little boy. His body was still changing and adapting to being revived. Which could mean Jason’s first jump scare appearance wasn’t entirely a hallucination. He just wasn’t strong -c-

-c- enough to finish the job.

Eventually, Jason’s body not only repaired itself, but he was starting to age to the point he would have been if he hadn’t drowned. Long hair and hall.

But because Pamela “botched” it, his body starts to morph and change into a different -c-

-c- appearance, much like how Deadites can change their appearance.

Then Jason is “killed”. And revived. And as a “zombie” his appearance is even more morphed.

And after being swept away by New York’s nightly sewage acid (.......?!?), Jason becomes even further deformed -c-

-c- gets blown the fuck up. And now that I got to the movie where the whole “Jason is a Deadite” thing came from, I realized major plot holes but I’m too deep into this thread.

I’ll...ponder these plot holes for a moment.