Make skills of different groups be affected by spell resist. For example, fire resist would lower archer's multi and warrior's roses damage. Ice resist would lower a thief's multi damage.
This is to give more variation in rares and make the resist rares be for more than just anti-wiz.
lightning=resist lightning
earth=resist paralysis (only resist effect left. It's not like anyone actually uses earth skills for pk)
fire=resist blaze
poison=resist venom
ice=resist freeze
wind=resist holy