Seals can be gained by winning a Player to Player (PtP) Action against someone in the same PtP Class as you. The win can be by initiating the action against someone else, or defending against someone else's actions towards you. The victor of the PtP has the chance to gain the seals, regardless of whether they were the attacker or the defender. The types of Seals you are most likely to win will be similar to the type of action that you made.