The primary objectives behind this weapon are to enable and give value to underutilized defensive gear (like justiciar), open up design space for future defensive gear rewards, and encourage future group PvM encounters designed with a dedicated tank role in mind.
By using the justiciar formula for damage reduction, this weapon turns each percent of damage reduction into additional attack and strength for the weapon (1% DR = +5 attack & +5 strength)
I made multiple slides that go into greater detail, but I can't seem to post the images, so I'll link my post on Reddit instead. I'd love for some feedback!
https://www.reddit.com/r/2007scape/comments/1rvcv4x/arbiters_lucerne_a_weapon_concept_that_turns/