Anti-AD Items
Here's my thought on two possible Anti-AD items, since all mages ONLY have Zhonya's if they wanna build Mixed (Offensive/Defensive). So here's a little more.
Runic Converter
"Converts physical wounds into Runic Armor"
+100 AP
+50 Armor
+10% Cooldown Reduction
Unique Passive: Taking physical damage will reduce all physical damage taken by 15% in the next 2.5 seconds. Increased to 20% if under 35% health. Physical damage resets the timer. 6 Second Cooldown after timer ends.
Cost: 3000g
Build Path:
+
+ 
Vampiric Crown
"Saps physical energy and stores it for later power"
+75 AP
+40 Armor
Unique Passive: 25% of Physical damage is stored into the crown, filling it up with blood (Max [40+20xlevel] blood).
Unique Passive (Unleash): After being hit under 25% Max Health, the User is healed by the blood in the crown, breaks free from all slows. 150 second cooldown. Blood will not refill while on cooldown.
Cost: 3100g
+ 
If you don't like these, please tell me instead of downvoting immediately. We can fix them instead of just randomly sending it to downvote hell. :P

still gives 12% spell vamp