People need to learn that Shyvana and some AD-scaling champs do alot of Magic Dmg...
Literally just lost a big part of the game because we had someone rushing TWO armor items because she was beat down by Shyvana... When Shyvana is almost entirely a magic damage dealer.
People needs to learn that those champs do ALOT of magic dmg even if their intuition tells they are AD (Shyvana scales on AD but shes does Magic dmg through it). Shyvana snowballed because our Vi had no def when she thought she had ton of it (Heavy on armor VS 4 magic dmg champs Facepalm) and Shyvana could carry until her team catched up to her.
(blue does a 50/50 mix) 
Add-in those going Devourer+Guinsoo, but I'm mostly talking about laning phase outside the jungle.
^ Those are the main ''offenders'' of what I could call the ''Magic Damage trap'' : Champs that can build Full AD/On-hit Attack speed while doing most of their dmg, or a big part of it, as MAgic Damage. I still see alot of people, while ranking up in silver, building alot of armor to counter them when it is either useless or not enough since you need magic resist too.
How can we make people learn to avoid those traps and not lose for it ? Communication in Silver is shitty and I would like to avoid those losses as I rank up for such a dumb reason :/.
. His e scales off Ad but deals magic damage.
got nerfed. When you are building AD you should be doing AD damage for the most part not 50/50. Because then if you get ahead there is no way to itemize against it. Making the snowball meta even worse. I'm not trying to rip on Shyvana here, but it's just generally not a good idea for the health of the game. And to top it off, most items are not very gold efficient until full build which makes it hard to build 50/50 on resists and you have to dip into hp to hopefully do more. (key word: most). And to add that in once you get your minimal armor and start to get some MR they have finished 
which makes building HP not as good and starts the stupid resist tug of war again.