Seekers soulshard (new item concept)

Builds from seekers arm guard

90 ability power 40 armor 10 magic pen (because maw has it so why not)

Passive: dealing magic damage to enemy champions grants a physical damage sheild equal to 5% of the magic damage dealt

Also passive: (to prevent tank abuse) ability power is subtracted by an ammount equal to 30% of bonus armor. Gain 5 armor for each 20 ability power lost this way

With no other bonus armor this will give 72 ability power because of the second passive.