The Fourth Rider

I have this theory that I made when I listened to Marks of the Evil one, The theory came from the lyrics, "The fourth rider is death, Rides a steed pale. And hades follows him." I thought about it and it goes from one to four and then i thought about the lyrics from Witch image, where it says. "I am riding in the shadows behind you on a pale white horse." Then that gave me my theory. What if V is talking about the other four Papa's and of course the fourth one would be Copia. Then I remembered in the RHRN movie, Sister Imperator dies and in Witch image Copia says "A mother would save her child from digging a grave." But my real theory is that i think Copia might kill Perpetua because he had a pale white horse and Perpetua sings about the fourth rider being death and riding a pale white horse. So this story will be about how i think that could happen.