After beating Radahn and just chilling out for a bit, I decided to find the church where you get absolution so I can fix my stuff, because I think I accidentally killed the masked sorceress woman and I don't want to give my special scroll items to that pompous poof Seluvis.
So I was making my merry way to the church when I saw a huge giant guarding a small rotund and went to check it out...
1.5 hours, 2 unexplored potentially large branches and one boss and a massive yet-inaccessible area later (full map for scale):
All is forgiven, Miyazaki. I anger easily, but am also quick to forgive :D