10~15% mdef bypass againts everything(mvp included), and keeping the other effects and slot sounds more than fair to me. It would still very likely be the BiS gear for magic dmg but wouldnt be by such a great advantage to others(like sapphire wrist vs other accs for gene), and getting small pieces of mdef penetration here and there, and having to make different combinations to achieve different amounts on each race, is a much more healthly aproach than just straight up blowing the entire mechanic in a single gear.
With 2 for example you can ditch Piercing Staff and use like a crimson rod, or ditch the obmh and use piercing staff+ zaha doll hat. Or use one of those+ Tsod and reach same mdef bypass but with some delay reduction, etc.
Edited by Ashuckel, 14 February 2017 - 09:14 AM.