Please Recommend Me a Book 😭 求书呜呜🚰·̫🚰

I read it before starting school. After spending a week there, I took leave and came out with only my spare phone. I wanted to find that book, but couldn't. I only remember a few scattered details: The First Ladder; the Red Blood Mantle Vine, a level-three instance where the protagonist got a B rank; and an instance boss called Red Eye.