@Riot, I have your 120 AP item right here!

From the patch notes:

One thing we do agree with is that there needs to be another +120 ability power item for endgame mages, and we're investigating that space as we speak. Rather, as you read.

Well, I have the item to replace DFG:

Rivini's Spectacles (or "specs" to shorten it) Named after me because I'm relatively famous and I know Riot secretly loves me. Context.

http://i.imgur.com/HOp3sZU.jpg[/img]

Imagine more "yordle-y" and possibly cuter glasses, but also sleek. :3

120 AP 10% CDR Unique passive (concept 1): Damaging an enemy with a spell grants vision of them for X seconds. Does not reveal stealth (or should it?).

Unique passive (concept 2): Same as #1 and also reduces damage taken from affected target(s) by X% for the duration. This effect only applies to the item holder.

Unique passive (concept 3): Same as #2 but without the vision.

Unique passive (concept 4): Vision range is increased by X%.

Unique passive (concept 5): Same as #4 and also increases the lifespan of sight wards by 30 seconds. (This should make the item attractive to mages and AP supports alike.)

Unique passive (concept 6): Spell costs are reduced by X%. Applies for mana only (maybe).

Unique passive (concept 7): Receiving spell damage creates a barrier for a brief time. Only blocks subsequent damage. If it remains unbroken for the duration, the remaining amount is expended to heal the champion, plus mana restored for half the amount (maybe). Has a cooldown of X seconds.

Unique passive (concept 8): Purchasing this item allows the buyer to hear a random excerpt from The Misadventures of Veigar and Lulu! (This is a joke. Relax.)

I got the vision ideas from the item being glasses, so I thought it would be natural to gain the ability to see better with them on. The non-vision ideas are general ones I brainstormed but could also fit in with the theme of studying the enemy and learning efficiency from being like a bookworm, like the yordle Rivini. :3
For example, studying how to cast spells at full efficiency without expending as much mana, or utilizing the energy created to make the barrier for another use instead of it evaporating into the ether and going to waste, or figuring out how the enemy attacks to reduce their damage efficiency.