Abyssal Scepter is warping the whole AP meta
In case you haven't been watching LCS, let me bring up the most frequent AP picks for solo lanes:

And here's a fun fact: Lissandra and Morgana are being played in the top lane. With Rumble and Kennen obviously there as well.
Does that mean the midlane is occupied by AD champions now? Well, aside from occasional Zed/Ezreal picks, that is not the case. What happens instead is a very high shift towards double AP comps. How does that happpen?
http://i.imgur.com/eqPnMgz.png
Well, Abyssal Scepter is the reason for that. It's an item that both a) promotes double AP comps (providing MR debuff for your teammates)) b) counters double AP comps (with high MR rating). The problem in here are the indirect implications: domination of Abyssal Scepter phases out long-ranged mages who can't utilize its passive.
#Why did this happen
It's not like Abyssal got a huge buff overnight, season 5 just gave it a smoother build path. I'd like to bring up Riot's comment on that:
We don't see this as being a permanent fix for Abyssal Scepter, but felt we could make this change just to clean up the recipe. While there's less Magic Resistance in the build path, it also consumes less inventory space! --- Pwyff, Patch 4.21 notes
Now the reason for Abyssal's resurgence is the changes to other items. Barring the Tear builds on champs like Cassiopeia and Kassadin, all midlaners have always rushed Athene's or Morellonomicon, unless the situation called for early Zhonya's or DFG (rip). With Athene's overly nerfed, Morellonomicon became the dominating CDR item.
That didn't remove the need for MR on mages, though, especially those who are getting in a close range. Toplaners like Maokai, supports like Annie and even carries like Corki/Ezreal all deal high magic damage. That's where Abyssal Scepter comes into play. Paired with Morellonomicon, it has become a frequent core build on both Ahri and Lissandra, and lately even toplane Morgana.
#Why is it problematic
Abyssal Scepter is one of these items that are redundant in counterplay. To counter Abyssal, build Abyssal. This gravitates the mage meta towards close-ranged mages like Lissandra, Morgana and Ahri. Since Athene's and Banner of Command, the only alternative AP-MR items, are underwhelming, long-ranged mages are left out of this struggle.
Then there's the case of manaless AP champions like Katarina (55% winrate at the moment, rushing Abyssal in all most popular builds).
#How to fix it
First, Athene's Unholy Grail probably needs a buff to one of its statistics. Either AP, MR or mana regen. It needs to be comparable with Abyssal and Morellonomicon, and right now it just isn't. One of its problems is that the Mana Font passive scales with mana pool, but items like Archangel's Staff and RoA provide so much mana that you don't really need that regen.
As for Abyssal itself, it should probably be split into two components:
- anti-AP item
- double-AP synergy item
Shouldn't do both at the same time.
#Example changes
A small buff to Athene's, and
Abyssal Scepter
- +50 ability power (-20), +50 magic resist
- Active: Steal 20% of ability power from nearby enemy champions for 5 seconds. 90 second cooldown.
The AP steal can be limited to one of the two sides of the effect, AP "copy" or AP debuff, if having both at the same time is too much. Anyway, the idea here is to get rid of the MR debuff and replace it with a different anti-AP mechanic.
New AP Item (example name: Robe of Pyromancy, heh)
- Example build:
Needlessly Large Rod +
Fiendish Codex - Alternative:
Needlessly Large Rod +
Aether Wisp - +120 ability power +10% coodlwon reduction (alternative: +6% movement speed)
- Unique Active (placeholder name: Reign of Fire/Magma Chamber): Creates a zone for 15 seconds that reduces magic resistance of all enemies within by 5% every second, stacking up to 6 times. (900 range, 1000 radius) 60 second cooldown.
This now is a tool for double AP comps. It works similar to the Black Cleaver and the scope is identical to Trundle's Frozen Domain. Basically you mark an area and all enemies within gradually become vulnerable to magic damage. Not very much useful for assassins, but for AoE/DoT mages it could be interesting on its own, even without external sources of magical DPS. My immobile midlane mage bias is showing, but generally this should be perferred by "zone control" mages like Malzahar, Velkoz, Brand, Zyra or even Orianna.
This is just an example, but the point is: double AP and anti-AP parts of Abyssal Scepter need to be separated.
#Summary
The current states of AP-MR items favours champions building Abyssal Scepter, as Athene's Unholy Grail fell from grace. Furthermore, the item promotes a "fight fire with fire" approach where the best response to double AP with Abyssal is Abyssal itself. This doesn't seem to be the proper direction.
Abyssal Scepter
is a bit cheaper, but offers no offensive stats)
and
were played as AP top laners. It is not like double AP is a new thing.
, Banner because it's a strategic support item with defensive stats in the price range of real AP items.
availible in the rift.