This may not look like a good build at first glance, but the off hand Zwei has it's uses. You can go into a stun lock from the offhand into the main hand zwei. It is also incredibly simple to dead angle with the left hand attack making it a very effective turtle wrecker. Power Within is a personal preference. If my health is getting drained I might as well make it worth while. plus no one seems to expect me to have enough poise to stop a 2 handed greatsword swing making setup parries easy peasy.
If you wanted to make this even deadlier replace the wolf ring with a red tear stone ring for a 20% power within boost and a 50 percent rtsr boost.