There should be a support-oriented AP Mage item for champions who don't heal or shield their allies.
Champions such as
who have fallen out of the meta because of the dominance of Ardent Censer.
Back when Zeke's Harbinger was reworked, mage supports were among the stronger in the meta, and as someone who plays Brand support, I was crushingly disappointed when they took a sub-optimal but potentially very cool item that was targeted at AP supports and turned it into a gimmicky tank item. (To this day I have never seen what the passive on Zeke's Convergence actually looks like in-game).
When I'm playing Brand support, I want an item that I can equip what gives me the damage and mana I need to function as a damage/cc oriented mage support and actually makes it feel like I'm supporting the adc instead of just dealing damage and leashing kills. Zeke's Harbinger was an item that had usability and reliability issues, but was attempting to fill this void in the AP mage support meta. The idea of being able to link to the adc and deal more damage together, which was never fully optimized and ultimately deleted from the game.
I don't know what the item should be. I just know that I would really love to have an item that made a mage-carry duo feel strong together like an enchanter-carry combo does.
. It even scouts out and slows people for you to kill. I mean, for real. Just build it.
Discord passive, but then locked it behind another arbitrary healing/damage passive. I think it would be pretty interesting to have something like that there so that AP supports could shine throughout the game.