What is the real problem with mages
So we have heard a lot about mages being broken this season and still a lot of people don't understand why that is the case, so I'm going to paint the picture why they are insanely broken right now in the eyes of a toplaner.
Most bruisers won't get resist item before their 3rd item by which time the game is usually over and boots you usually have to get against your laner. Let's look at 3 general toplaner bruisers
for example. At lvl 11 they all have 43 Magic Resist while 65-75 armor. Every mage can buy sorc shoes which is 18 magic pen and they also can buy
to get +15 magic pen which builds into a good item
. So this is a build path basically any mage can take. Thats 33 magic pen against 43 magic res. That means a bruiser who is supposed to be tanky will have 10 magic resist against a mage that's only 9% reduction while if you get
on top against the adc or the other toplaner you are going to have around 90 armor which will be around 47% reduction against a non-assassin AD champ. They used to be balanced around this by being "glass-cannons", they kill you fast but they can be killed fast. But that's not the case any longer. By removing the they can be killed part you will inevitably make them broken in some regards for example against all bruisers.
got E cd buff not so long ago while he was also destroying bruisers, the items
didn't use to be in the game removing his natural weakness against bruisers.
are also good examples of unkillable mages with insane damage. And we haven't even talked about
and
. Just last patch conquerer becoming broken only on AP champs (because they don't deal with resistance meaning true damage was useless to them anyway) shows shows how big of a balance issue it makes.
My proposal: bring magic resist to armor levels. It may be unbalanced at first (but hey that's what preseason is for) and would definetly need readjusting some general things. Maybe not the best solution but that's my first idea and something must obviously be done. Nowadays every mage have a lot of survability in their damage items
shield
health,
cc,
(you can have both in your inventory). Not talking about new and reworked mages with their increadibly survability while dealing insane damage(like the above ones). If you try to tweak these variables one by one you are most likely never going to succeed (which might be riot goald though). The old formula just doesn't work in the new system, many old systems were changed because they didn't fit the evolution of league, this is no different.
mid main with Domination & CDR + Damage flex runes and rushing
while staying on tier 1 
+ null orb rune + tenacity rune can pretty much negate most mages early and mid game damage + cc.