Wizzards.

I think the best way to figure out what kind of items mages need would be to figure out what mages actually do ingame. Which is a pain because they tend to do multipul things which is when the syndra mains of the world say "UM ACHTUALLY SYNDRA CAN BE A SUPPORT".

For starters the defense mages. These mages might actually have bought banner of command if you ever gave it a reason to be built by mages. Generally they are able to summon things and are practically win more champions with the exception of malzahar.

Teamfight wizzards. Generally these champs take full control of the teamfight with high cc and damage but low mobility to compensate.

Then there are alot more supportive style mages. These tend to assist alot more then attack.

Everyone knows what the idea of burst mages. They are literally the epitimy of what ap is supposed to be.

Now for the mages that make no sense to any mid laner: the alcoholic yoloing divers.

Then there are the poke champions that suck because they are only able to poke. This champion is about 3 years old and is in a dire need for a rework. Oh wait.

Noticeably i haven't given any solution to these problems but since people have the attention span of a dog going for a walk. I'm going to make a differnt post later detailing what the items should look like moving forward.