In Ranked PVP it is possible for your opponents to be flagged as Revenge targets, Rivals, or both at the same time.
Revenge targets are players who have beaten your defense team. Beating theirs in return stands to earn you an additional 3 Glory on top of the base reward.
Rivals are players you have exchanged a couple of battles with. Beating them will earn an additional 2 Glory.
These bonuses can stack with each other and with the extra Glory from leveling your guild's Brown Guardian Statue for a maximum of 11 Glory from the hardest opponent.