Patience Rayne rules

There's this thing in the paper called "Decodaquote" by Patience Rayne. Basically it's a substitution cipher. My mom loves them, and lately Kaida has forced me to send her the Decodaquote each day, as they don't have them in her paper.

Patience Rayne sounds like a video game name, doesn't it? (Actually, wouldn't it be cool if her full name was Patience Blood Rayne? She and I are good friends, so I think I'll ask her about this.)

I'm not sure of my legal footing here, but I'm pretty sure that Patience will be cool with it, especially if it gets people interested in her stuff, so I'm giving you a Decodaquote from the other day. There are no points being awarded here, so don't reveal the answer. Just leave a comment when youv'e figured the whole thing out. The two words after the quote is who said it, and there is a clue to get you started. Each letter represents another letter, and it represents that letter throughout the quote. So if X =Z, then every X would be a Z. Have at it.

"RB BJY YLX, LG GLY UA YMYT CGULC BG BJRLP KGE HGT LGB VUMULC KGET VUHY."

RVUWUR DREVAGL

Clue: (D=P)