I suggest a full DS build, trap your enemy, you can spam DS pretty fast with a decent agi and the damage output is good, unless the person's got yggs they shouldn't be able to outpot you. Unless the person has pneuma in which case you're screwed, but it would be the same with FA or blitz.
I trust your server has a reset npc? Best thing is to make your own build, see what works and what doesn't with the people on your server.