"weaker mage items overall" may not be that bad in this light.

so yes, zonyas loses some AP and gets reduced cooldown. but its cheaper

i just realized with these mage items, due to the items getting cheaper in many areas, many manges could see to approach 6 items (selling boots) in many games

i think that will be the direction for mages to still hold a path to lategame power

since getting 6 items on a AD champion is extremely expensive, mages could reach 6 items much faster and have a power spike and siege / fight with their team to get 1 or 2 inhibs and close out the game before a AD champion can get 6 items

also because the cooldown on zonyas is so high now, it may simply be better to get the new rocket belt that has a 30 second cooldown flash with possibly a bit more tanky build and just not getting zonyas at all. Pretty much you just need zonyas against zed or if your a champ that wants it like fizz / TF / lissandra / vlad

now moving on

lets look at this possible endgame mage build

RoA Liandrys Void Staff Rylais Deathcap Rocket Belt

this mage build will output sick damage, with lots of penetration, with the rocket belt for the low cooldown flash. with rylais for extra slow and CC on your spells combined with liandry which lets you damage tanks better

this build will delete enemy squishies, and do high damage to enemy tanks, while having the low cooldown flash

also. this mage build comes with a nasty +1600 health . so your pretty damn TANKY as a mage while also dealing sick damage

i feel mage builds like this will totally allow mages to compete in lategame power with AD champs