i don't do damage anymore to them, my team expects me to kill him because i'm the adc
My tank built armor against enemy marksman
they still destroy him i see no problem whatsoever, MR itemization is balanced, adc itemization is balanced good job
Buy Void Staff.
And Adaptive Helm only reduces damage from one ability. If you hit your E on him it will only reduce your E damage until the buff runs out, then it will switch to whatever magic damage hits that person first. That is how it works.
But the most important part: Why do you even attack the tank. Just kill his team
Morde isn't an ADC.
they have higher dps than mord
like a balanced champion, mord actually has a downtime on his damage
armor itemization is stronger than mr itemization hehe
Nothing new, it's just the crit scaling.
You were full AP right 
?
in both situations the person who has MR vs your MORD would die if you constantly do damage to them just as the tank who has armor vs the enemy adc... they still die to the adc cuz the adc does constant damage to them
Try building a Guinsoo's Rageblade in place of a Nashor's Tooth if you build it, it'll reduce your AP by a few points, but increase your AD and attack speed, meaning you'll be able to have more sustained damage in combat. I haven't tried it on Mordekaiser himself yet, but on other champions that I find have a similar playstyle and similar scaling it works quite well.
Did you buy + or ?
He built Mr to counter your attack damage carry? 🤔
Mages just don't tank bust. You can be in the ADC slot as Morde, but in the end, you still aren't a real ADC. You are not a tank buster. ADC's are tank busters.
