We have Anti-AP mage, Veigar. How about Anti-AD mage?
I think previous Xerath was somewhat like Anti-AD mage with his range, e and passive. But, yes he's gone.
Do you have any Idea about Anti-AD mage? (especial counter for ad assasin)
Malphite.
Your welcome.
yes, please
Given the presence of AP toplaners (Lulu, Ryze, Lissandra, Vlad, Teemo), it's difficult to imagine an anti-AD mage that wouldn't just be ported to toplane instead of mid, and then used against AD bruisers.
In order for this anti-AD mage to work in midlane, he needs to be squishy, get no benefits from tanking and have extremely good waveclear (unintentional wave clear would be great too). He would probably need to have fine-tuned defensive stats/passives. Having generic armour bonuses or a reduction to physical damage would make him good against AD bruisers and ADCs.
Ideally you'd want him to have a complicated passive where he takes less damage from physical damage that exceeds a certain threshold. That way, the low and consistent damage of an AD bruiser or ADC is unaffected, while the burst damage of an assassin gets greatly reduced. You can make this threshold be a percentage of his max health, to encourage him to stay squishy and build resistances instead of HP.
Anti-AD mage? Shen AP mid with Exhaust and ignite vs Zed. Easy gg
I think Ryze works really well, he sort of builds into an off-tank (especially with Frozen Heart), so he's difficult for an AD assassin to burst, his Rune Prison is really good CC, and he deals good damage.
Or, like Epjest said, you can play AP Malphite. Or AP Rammus. Maybe AP Sion.
Technically speaking There are counters to ad mids, just not anyone that scales specifically from the ad/health/armor said ad champ you are vsing has. You basically want a AD version of 
which i agree with because it would bring a cool twist into play.
Dude, Teemo. Teemo Teemo Teemo. Noone can land any AD on Satan. Slowshrooms, poison for squishy assassins, a blind to make sure you can't follow up on your burst, a speedy escape to leave you hanging in the middle of said burst, a whole ton of kiting power, stealth for positioning and avoiding dumbfire abilities.
Teemo hurts Talon, he can hurt Zed, Wind Wall doesn't block poison or mushrooms and 'nados can't catch him.. Need I say more? He also counters any midlaner that relies on skillshots, if you're equally skilled. Ahri, Xerath. Nidalee can't withstand the yordle, either.
Teemo.
Geeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeems
So you mean any assassin?
oh yes plz!
AD malphite top...
a hero with a damage drain or aura of AD reduction of some sort would be an interesting addition.
Any mage with Zhonya?
Argos, the Rune Mage
"Some champions have worked hard to gain abilities through intense training. Some champions have been gifted by mutations, curses, or other chance means of empowerment. Then there is Argos, the champion who has crafted his own means of power."
Passive: Gain AP equal to 50% of your armor.
Q: Fire a quick blast along a line hitting all enemies for moderate damage. Slows all enemies hit.
W: First cast: Pull nearby enemies in towards yourself. Second cast: Pulse around yourself, knocking enemies away from you and slowing them, dealing low damage. Gain armor for a duration.
E: Push a single target a moderate distance away from you. Deals moderate damage.
R: Remove all debuffs including silence. For 3 seconds you may cast again to shock all enemies in a large cone. Enemies take high damage and are stunned briefly and slowed for a moderate length.
Argos has the appearance of a stout old man. At level 1 he is very lightly armored with runic tattoos and a large iron staff. The staff would be bulky with a broad head on it similar to a warhammer. He is a melee mage.
As Argos levels his armor improves. The armor has runes inscribed upon it. Depending on which ability he levels a different piece of armor will both grow and gain a rune. Q: gauntlets. W: chestpiece. E: legs. R: Helmet.
Argos would have decent damage but would not be as bursty as some of the main AP mids. He would be a fierce control mage fighter with natural tankiness.
Counters would be Ahri, Fizz, Orianna.
He would counter Zed, Talon, Yasuo.
He would be a top or mid champion.
