Hashinshin complaining that Bruisers do no damage to Tanks and that Tanks are weak against Mages
Ah, the Irony... Mages need huge amounts of pen and magic pen just to deal with Tanks health pool and health regen from Warmogs abuse + spirit visage. While bruisers shred the living shit out of tanks with just Black Cleaver or Conqueror.
Hashinshin doesn't know that BATTLEMAGE = BRUISERS, They are meant to do what Bruisers does and they are the MAGIC VERSION OF BRUISERS, they are much squishier than bruisers but they play arounds Shield rotation or Healing Rotation.
or 
Look at the core items of these 2 champions, Protobelt and Archangels,
Most mages don't even go these 2 items and rather stick to Luden's Echoe because they are either super strong early game but useless late game or super weak early game but super strong late game.
Luden's echoe provide power through the whole game, it is a strong powerspike.
The reason why there is Less MR in the game is because MR is so much more stronger than Armor, you can build shit tons of armor but it doesn't matter because true damage on hit exist and conqueror as well as black cleaver. If you build 15 Magic resist but have a shit tons of health regen and health pool which pretty much all MR tank items gives, it's all about playing smart. All you gotta do is wait 5 sec out of combat with warmogs to then reengage them.
Bruisers are such a crybabies that they are complaining that they can't deal with a class. It's the same situation where you can say, ADC can't fight assassins, because they don't have the kit to deal with them.
assassin's but they aren't.
and
, but that is kinda it.
70 ap 300 health, magic pen, grievious wounds and now to add that to 58 magic pen we already had, 58+15=63 magic pen....YEAH that when with a full magic resist build on lets say, sion, you can have about 230 magic resist which falls down to 160-180 and because mages have items that give up to +1k mana, they are able to spam abilities so much that even that 230 mr will feel heavy damage. And I haven't yet mentioned Liandrys torment which gives BONUS DAMAGE AS LONG AS YOU POKING SOMEONE. You say that the magic resist items have great passives and yet you don't mention what a average mages items give as passives. And since when is Ryze's core item a protobelt?! Every ryze I see goes archangels and frozen heart feeling no damage, spamming heavy damage and shielding alongside with speeding up himself in the process.