Gargoyle stoneplate, HP jungle item, abyssal mask, and with 95 MR an Azir with no void staff and whose KDA relatively matched mine was deleting ym health in less than 6 seconds as a Nunu. I'm getting sick of this shit, at least lower the gold cost on tank items.
Make 
a tank item again for a start. The mid-season 7 tank update was one of the worst large scale updates in the game and a big part of that is because it completely ruined tank itemization and removed the dedicated anti-burst MR option from their item pool so that mages could build it and then proceed to never do so in the 2-and-a-half years since.
The next step would be to bump the pure damage items down to the gold value that tanks get. For armor item, that value ranges from around 70% Gold efficient (
) to 85% (
)
MR items a bit more efficient in that regard, and 
is above gold efficient, but that efficiency comes from the base health regen. Without additional healing in a tank's kit, it isn't much better than 
's 88% gold efficiency.
The reason the raw gold efficiency is so important in this discussion comes from how damage and resistances scale. It's been said by some, erroneously, that resistances "fall off" in their damage mitigation. This isn't true, but what is true is that point for point, damage scales at twice the rate of resistance. Consider two identical champions auto attack trading:
20 autos to kill
Add 50 AD to one and 50 Armor to the other:
16.6 autos to kill (17 whole autos)
How about 100 extra armor instead? = 3000 effective health =20 autos to kill
Point for point, you need twice the bonus armor as an opposing AD build needs AD to match them.
Now, the base items already indicate an issue. 
grants 15 armor for 300g (20g per point) 
grants 10 AD for 350 (35g per point). That is, AD costs 1.75x the cost of armor. Oh, AD outscales armor at a 2x rate, but only costs 1.75x. Hmm, maybe things look better on the magical end?
MR and AP isn't quite the same comparison since AP ratios differ among champions, but the general rule that governs the cost of AP vs AD is that both should cost around 60% of their physical counterpart.
Ahh! Well, see, while AP costs 60% (okay, 62% and some decimals) the cost of AD, MR costs 90% of the price of Armor, at 18g per point. That explains in large part why even without MR shred, AP champions with at least 62% AP ratios will just out trade against the same cost of a pure MR build.
And that's not even going into the fact that tanks need to split the resistances they build making them half-again as effective against BOTH damage types.
Before mid-season 7 this was less of an issue, as both the largest MR and AR items -- and 
/ , granted more health which helped against the opposing damage type and multiplied the effect of the resistance they granted by that much more. For the armor items' case, that's 75 more health but 10 less armor (Granting a total of 750 effective health on its own compared to the 680 effective health from the live version). For it's 50 more health and 5 less MR (750 effective health vs 697.5 for live). With the higher health, both together granted much more tankiness than the combination does currently: 1500 effective health against both damage types, compared to live's 1400 vs physical and 1356.25 vs magic damage.
But riot wasn't done, no sir. Later that year would see pre-season 8 and MASTERIES RENAMED I mean RUNES REFORGED. With this new rune system, not only were armor red/yellows/quints and scaling MR blues gone removing ~27 of both resistances, but a lot, and I mean a lot a lot, of resistances were completely cut from the Masteries themselves. Siegemaster gone -8 both resistances. Unyielding gone -5% bonus resistances. Veteran's scars gone -50 health. Fearless gone -10% +1.5 per level resistances. Legendary guardian gone -3 resistances in 1v1s, -6/9 in skirmishes, and - 15 in team fights. Stoneborn pact GONE -5% health.
And in the place of all of that? +9 base armor to compensate missing yellows; 9 resistances +5% only after laning phase is already lost; and a whopping 33 health after 13 waves of nonstop uninterrupted farming (~8 minutes of never leaving lane from the start of the first wave to the end of the 13th.). Oh and that farm eventually gives +3.5% health if you never go for objectives or help the team in any way for 20 minutes. Woo.
So 27 +8 +3 +1.5 +5% +10% = 45.485 resistance and 50 +5% = 52.5 health minimum (level 1, and against 1 opponent) gone , and 9 +9 +5% = 18.9 armor, 9 +10% = 9.45 MR, and 66 +3.5% = 89.1 health maximum after 20 minutes added. I mean maybe someone at riot just.. Forgot to compensate for the missing stats entirely with the new runes?
Oh nope carry champions get infinitely scaling AP/AD or 20 bonus adaptive force above 70% health and +9 base AD and +16 adaptive force and 6 armorpen/mpen for walking into a brush and 20 bonus adaptive force for warding/oneshotting 0.01second faster than their opponent. So they didn't forget to compensate them fuck no.
There is soooo much damage stacked up in the game (not including the immense item pool for armor/magic pen) that resistances are an obsolete stat for more than a year. As far as I see things, tanks are a dead role, with very few exceptions and I am dead curious to see when Riot will release a new tank champ.
Remember when the last tank champ got released? Oh ye, 
. Been more than a year already.
Tbh dps mages like Cassio and Azir are some of tanks worst enemies except maybe adcs, so I'm not sure it should be that suprising?
Combination of inefficient tank items along with damage being tacked onto literally everything.
6 seconds against a DPS mage, and you didn't run away or fight back? What, should tanks take as long as Baron to kill and require as much of a coordinated effort? I get it, you want to be a tank and soak up a lot of damage. Well, you did and you died for it. Even tanks can die.
Kill the enemy faster than they kill you, you're officially tankier. (at least this seems to be the balance philosophy)
I build HP and Armor all the time as a mid mage and still get deleted instantly by Zeds and Talons, so I can only imagine the annoyance tanks must feel. People say to rush this, but it's not Season 6 anymore where Lethality wasn't as crazy.
Tanks seem to get get replaced with Bruisers who can not only tank just as efficiently but also deal respectable damage to the backlines.
Magic resist itemization is literally whats killing tanks. We dont need more hp. We dont need more armor. We need fucking MR. Mages are so goddamn broken yet we have no resistance for them. Funny, isnt it?
Play tryndamere, buy zhonya.
You are now the best tank in the game at 7sec survival.
6 seconds is a lot, an azir will delete a squishy in less than 1 second. So it looks totaly fine that you die in 6 seconds.
Why did you let him attack your for 6 seconds? What was the rest of your team doing during that time?
If you tried to 1v1 a DPS carry as a Tank and you lost, that's normal, even if the carry was not fed. On the other hand, if an Assassin, even not fed, had jumped on him, he would have lost no matter what.
Champs all have different roles in a team, and that's a good thing.
6 seconds is a lot in a SR game. also Op you built the wrong item
if your trying to shut down a azir who is dps get not
By having three tanks on one team. Support, Top, and Jungle with AP mid and AD bot. Then cross your fingers and hope that neither mid nor bot feed hard before the tanks can get together and make bitch sandwiches of the enemy team.
Try to find 1 or 2 damage+hp items that works with your champ's kit. I find that 
works okay on tanks with 1 low CD skill. I'd even build it on sej because her W is spammable and the AS helps with her E.
I kind of wish that 
was added back to SR for tanks.
And on the other hand comes along Garen with trinity and phantom dancer that ignores your damage with his w AND proceeds to kill you in a single rotation.
