If my mystic was on a PVP server instead of PVE, I would probably be the same spec that I am now. STR, AGI, STA and Ancestry, Weapon Mastery, Immunization
Go with a couple of different specs but prolly try something like
agi 488 wis 44682 int 44682
then ancestry, weap mastery, immunities
The idea with that one is to have scourge for stripping buffs/heals and alacrity+immunities to let your wizard friend blow shit up without interuption while you root the enemy and knock them Up with a big two hander and CA's!