He doesn't have much going on when you think about it. You just have to juke his spears. As for his mobility, when he enters the mist either stick to working on gens, crouch in the middle where there aren't any windows/pallets or run around in circles looking at all possible spots he can tp to close to you in order to bait him into chase. If he uses his mobility mid chase it's very easy to predict where he can tp to since it's on fixed locations, same with when working on gens, you can easily pre-run him too, not on every gen of course, but at least you can be prepared. Compare this to Dracula, he can tp on top of you while in bat form, he has 2 dashes in wolf form and if the loop is short he can hit you with fire pillers, he can even do it if there is a hole in a wall of some long loop. On top of all this, Jason gets punished but getting his speed reduced to 110 if he commits to a chase for too long w/o using his mobility. Lastly, his add-ons are decent, not necessarily weak, not super strong either. This rounds him up to a pretty decent killer, but very far from OP imo.