Not sure if you have already saw the walkthrough already but to answer that 猬囷笍
Never let go of your notes 馃槄
And that part where it says "You have no choice" whatever, just wait for a couple more seconds 馃憤
You have to die enough times and get all dialogues with Reaper so he gets included and you get the poly route with him and Trapper :,D
I realized that later after looking back at the walkthroughs and noticed how much we have to die so we can actually pursue Reaper 馃槄
You'll notice when you have to stop dying in an area if the next dialogues with Reaper/death scene do not change anymore (probably. idk, I'm guessing for now since the Waterfall walkthrough isn't done :,) )