The whole PVP endgame has already been solved, long time ago in fact. It's called WoW Vanilla.
The main goal of the PVP endgame system is making the game endless and highest rank the ultimate presige. Vanilla solved this. Deranking ensures the game never ends - you can't "complete" World of Warcraft by achieving R14 and permanently hold that. Or rank 13, or 12. It's a living breathing system and it keeps the game going, forever.