After the recent vote we had, and looking through the suggestions, we've decided to go with the nobility theme, but replace "of PvP" with "of the Arena."
1st: God/Goddess of the Arena
2nd: Demigod/Demigoddess of the Arena
3rd: King/Queen of the Arena
4th-10th: Prince/Princess of the Arena
11th–25th: Duke/Duchess of the Arena
26th-100th: Baron/Baroness of the Arena
101st–250th: Knight/Dame of the Arena
The current plan is to have this in place for season 17.
If you earned the current titles, they will not go away.