So can like someone pls explain this to me because this has got to be one of the MOST confusing VN I've ever played, and I've played a lot. It revolves around mainly what exactly happened with Sydney's death, it's implied that several different things happened with only 1 of them being 100% true and that's the fact that Chase did NOT kill him, but it's implied that it was TY and/or sam or a third entity that vowed to protect TY at all cost. The only actual conclusion, that yet again can be even more confusing, is that the true ending is Leo's good ending . But you need to play the sequel and get the perfect ending to even know this, and yet it's implied that also TY's ending is also real?! Like the VN seems interesting at first glance until you actually TRY to piece it together and it just falls apart, almost like it was created by multiple different people with different points of view. TLDR story starts off good but derails quickly once you get to the endings and try to piece it together; and who killed Sydney?!
Major spoilers for the whole game (duh)
In TJ's route we are given a treasure hunt, where the final reward is a drawing of Chase drowning Sydney while TJ watches. This is further confirmed by Micha telling us that he had a dream where he was being drowned by Chase and also TJ telling us in Flynn's route that he saw 2 brown-furred bodies in the water that day.
Even though Chase thought Sydney was being very "weird" the last 6 months (possibly because Samuel was possesing Sydney at the time) and also said that he was glad that he died (because of the "weirdness"), it's still quite uncharacteristic of him to just go ahead and murder him. (he is very indecisive, so he would never be able to make such a drastic choice)
I assume the murder was done by the same voice that killed Flynn in TJ's route, as they both appear to share the unreasonableness of it all. Chase did technically kill Sydney, but he really didn't want to. It was all because of that new voice. We know that the spirits possesing Chase can take control (Like when Chase is about to be killed by Brian), and since the new voice is much stronger than Sam, i'm certain it could force Chase to do something like murder.
And to put the final nail in the coffin: how would Chase end up with Sam's ghost if he didn't kill Syd? We know Sam changes hosts to the person that kills the current host (Sam->Syd's dad->Syd), so how would Chase end up with him if the person in the lake was someone else?