Doomsday Is Opened by the Door

What will happen if there are two personalities in the end of the world, and the main personality does not know the existence of the second personality, but the second personality sees the scene that the main personality sees? (This is the first time for the young author to write a novel. He is not a full-time novelist, and his imagination and expression are not very good. He also does not have much time to sort out and imagine the plot. It is impossible to update it daily. Sometimes it is very casual and may look a little strange. I don't think it is well written.)