Black cleaver is good for shredding armor. Oh look, no way of dealing with MR.
30 Pen + 35% Vs 92 Lethal + 30% reduced + 45% bonus ignore.
This doesn't even include the countless array of champs that can reduce armor, vs the 5 total that reduce magic resist. (only 1 mage reduces MR)
Tank players often cry that they get ripped apart by carries.
Move some of the tank killing power from carries, to mages.
ƒrostγ4 votesMost mages were ment to be strong during the midgame, and in that phase of the game they are able to shred tanks.
Inting Pillow3 votes
R183 votes
alfavhunter2 voteschange to ignore 50% **bonus **mr
change 
to deal 1% +.5% per 100 ap of the targets TOTAL hp as magic damage over 2 seconds after landing a spell on the target until the target has less total hp than the casters current hp instead of its current hp shred, this value is increased by 100% if the target is effected by a form of CC or slow
oSEXYPLATYPUSo1 votesmages are typically burst /nukers and try to blow up a target
tanks are tanks and survive the nuke
if you want a mage to kill a tank then you need a DPS mage
with 
will typically do the trick if you are DPS
Darkdemon6531 votesI will agree with this as long as tanks get more than one MR item.
Unreformed Shaco1 votesI kinda feel your pain, the few times I have played tanks building MR has been iffy, though these days its not too bad.
Especially since most tanks scale AP, you've got BV, AH, AM.
Escheton1 votesMages do have a good tankkiller. Normal Mage builds.
Tanks are overloading on armor because of how much gets shredded and how strong ad items and champs currently are. So they build significantly less magic resist. So as long as the mage in question isn't 0/7 and just too behind on farm for items due to that, they should chunk tanks quite efficiently.
Unreformed Shaco2 votesBut armor items usually come with health, and health itself is a natural counter to burst.
Even if you look at only sheet damage (premitigation), most mages wouldn't have the damage to smash 4k health.
Take the 50% resist in and they just laugh it off.
Escheton1 votesThey don't have to smash 4k. Or are you talking about wanting to 100-0 a tank in 2.1 seconds when you catch on warding? Somply dealing 1.5-2.5k in a burst rotation (or two) is enough to shut down a tank, given that the ad they are building against does the same. Tank that can't tank long enough to distract while their team moves in is pointless.