All of it. I loved the earlier part when they were in the cave, as the struggle there felt impactful. It felt to me like a fight between love (Elena) and pain (Mars). Elena wanted to heal him, as well as atone for her own sins in being part of the cause for his condition, but to heal a heavily bandaged injury you need to remove the bandages and expose it, which is scary, and healing its self can be a painful process. So Mars' pain was lashing out, trying to corrupt her before that happens, because on the inside he was afraid. He was even lying to himself at times, which is a natural thing for people to do in such cases.
That struggle was fascinating, and I was on Elena's side all the way. I thought/expected/wanted that the route's story will be Elena gradually healing Mars, and Mars gradually giving up on his lashing out and corruption attempts and accepting her love. I thought/expected/wanted that route to be the healing route, the really emotional route where both sides win after overcoming their severe pains.
Instead we got elena being turned into an exhibitionist out of nowhere, torturing her own son "because it is better for him", literally going insane, and becoming known as a whore to everyone.
So yeah, I hated pretty much everything about Elena in this update. Though Ironically enough the couple lines at the end with Mars breaking down and finally accepting her were actually the only part that I liked.