Xeroc or Noxus dialogue (Calamity Mod)

[Agustus]

So i was playing Calamity mod on Master Death mode, pretty easy tbh, until i reached plantera. I went to another world that i've already beaten and took some items, shortly after that my screen went white. When everything was visible again i was on some stairs, when i reached the top it was like Xeroc was talking to me through dialogue. I returned to my world and saw that all of the calamity bosses i've defeated was marked undefeated. How did all this happen???