I got the (unfinished) ending where Isla is turned into a shadowskin. Obviously this is still in progress, but I enjoyed what you have so far! The tense changes in the ending I got from second to first person, which stuck out to me. Obviously that part is still being edited, for immersion I recommend you keep the tense the same throughout, although I think second person was fitting for this type of story ("you are being chased" often feels more personal/anxiety inducing than "I am being chased.") I enjoyed this story and the world building, I liked the way you snuck in exposition through exploring the house, I'm excited to see more as you complete it!