I think there must be a pvp specific gear and pvp currency with player damage resistances.
Recently I thought a mechanic could be interesting, adding a block mechanic where damage is taken on a blocking bar instead on health bar, and when that bar reaches 0 the character is stunned (like the block mechanic in dark souls). This block mechanics may vary depending on the weapon you are using to block, or the shield. And the blocking bar regenerate slowly so you cant keep blocking all the time. This mechanic could be useful for pvp and pve.