the 65 relic is superior to the 70 for pvp. If fighting a mage the 70 relic is absolutely worthless- the 65 is money when your 12k magic attack jumps to 15.6k roughly. And you can just buff yourself for 100% crit rate anyway since you have -52% casting time and wont need the cast speed buff since the limiting factor at that point is the animation not the cast bar (and the hit is insignificant since you never miss). You don't even need hit on the staff to never miss- just use a lover buff and between your cape and accessories it would take the perfect storm for you to miss. There's just too much crit dmg reduction and crit rate reduction at that level- which sort of nerfs the 70's effect. At a minimum ppl have -25% crit rate reduction which takes your 50%+30% from relic from 80% down to 60%...youch (I assumed you have around a base 50% magic crit rate). When the 65 procs it is brutal- where's your persevering now son? lol.
To fill in the blanks id use 65 pvp set, 65 relic, 70 staff.
Your best defense is a good offense- get that staff proc'd. A cowardly AM is a dead AM.