Curse is currently kind of unfeasable as a single target debuff as opposed to Bless, the single best buff in the game.
How about Curse puts charges on your weapon,that inflict curse on anything you strike ? That way one cast could help you in many battles instead of one.
They are opposite effects Khor... Im not sure how one would be better than another in a pvp aspect.
Bless can be casted BEFORE pvp, Curse has to be used during =/ and curse costs more. Can it be resisted? i havnt tested that. But bless is just one of the best spells in the game. Its amazing. Like, i can get a necklace for +10 str? Bless is +10 to all? thats 60 stats in one spell ! Bless has far greater utility and is waaaay more convenient too =/