Riot Why No AP Tank Items?

Riot could we please have some decent AP tank items/ AP "bruiser items. I mean AD tanks/bruisers have a huge arsenal to choose from, , which you won't see adc (both ranged or melee's like riven) or picking up . Hell doesnt even offer AP anymore. I know that and exist which offers good health and armor stats respectively. But rod is wasted when you don't use mana and is still a core item on several squishy mages while hourglass is extremely expensive and far more suited for offensive minded squishy mages. I mean as a tank you want to be tanking not invulnerable from damage during a fight.

So lets start a discussion about what could make good AP tank items, you know items that would be good on a tank not make burst mages harder to kill while maintaining their high damage. I'll start by proposing an item and feel free to shred it as much as you want but also try and offer new and creative suggestion for design space for Tank AP items.

Seekers Chainmail Cost 2600 Recipe + +600 Stats 60 armor 40 AP

Unique Passive: Fortified Knowledge - you gain bonus AP equal to 10% of your armor max 30 AP. (That means you have to have at least 300 armor to get the max benefits so you are rewarded for building tanky.

Unique Active: You lose your bonus AP from "Fortified Knowledge" for 30 seconds. Grant a shield to target allied equal to 100% of your armor for 2 seconds. Cooldown 85 seconds. (This gives you an interesting discussion between playing defensive or offensively as well as adding in a skill ceiling for properly sequencing abilities and item actives).

Yes might go ham with it but it could open new build paths for champs like to go for more straight tank items and for champs like to actually have some AP for their abilities in their build.