Even if u Build Spirit Visage and Adaptive Helm, u still will get almost true DMG from Mages if they buy this 
Lets Assume u go MR Shard and build Spirit Visage and Adaptive Helm.
A Tank will get with these 2 Items around 150 MR.
So 150 will be reduced to 90MR thanks to Void Staff and now - 36 from MPen. Voila even if u build 2 Tank Items u only have 54MR left.
Change Voidstaff to Bonus Mpen
well mr by its self with out HP is going to do anything.
and as someone who is a maokai otp i rather face burst magic damage and get mr then any other damage in the game cuz its easier to sustain with HP
Complaining about magic pen when armor pen is far more effective and common.
I mean, we dont really have to. Just buff MR stats and things will be fine (mainly buff the mr stuff for bruisers+).
Really the irelia with a wits end + visage + death dance and steraks was unkillable vs our full ap team. and we all had full builds with void staffs.
