Dekans literally are part of the assassin class in this game, they have high single target damage and are designed for the purpose to kill people/monsters. If you can't kill anything with your dekan you simply suck at this game
Priests are a support class that do not have any high damage output except for a few skills, which have, compared to dps long cd's and not to mention really bad damage in pvp as well in pve (with updated mirror dungeons priest aoe is useless.
So really, the person who has to stop talking trash is you because you literally are trash, delete your dekan and go play something usefull lmfao.