Rabadon's Deathcap needs to be reworked

It's widely known that this item is bad. It has a huge cost (being the most expensive item in the game), shit build path, and isn't even cost effective (93% efficiency). The thing is, Rabadon is too generalistic of an item to be buffed. If it's any strong, all mages will but it, no question. That kills item diversity. Also, it's a boring item and doesn't come with an interesting gameplay niche, it's just a ton of AP. I think the best solution is to divide it between two items: one for burst mages, and other for dps mages.

[NEW] Rabadon's Murder Cap +120 AP Unique Passive - Eyes of Pain: +15 magic penetration Unique Passive - Magic Hat: Landing two unique attacks or abilities in enemy champions within 3 seconds will empower your next ability for 5 seconds, which will deal 50 (+30% AP) bonus magic damage against all enemy champions hit. -Its new passive it's kind of like Electrocute, but enabling you to hit a different enemy each time. This has got magic pen in it in a named Unique Passive shared with Liadry's, however I don't expect Liandry to conserve flat magic pen after the AP item pass, so it shouldn't be necessary.

[NEW] Rabadon's Focus Hat +100 AP +10% Cooldown Reduction Unique Passive - Magic Hat: Every time you land an ability on an enemy champion, you gain 10 Ability Power for 5 seconds, stacking up to 5 times up to 50 bonus AP. -This new item is focused in Battle Mages, allowing them to deal tons of damage over a long fight. This item is the one with the most Ability Power once stacked. The 150 AP could be problematic with burst mages, however if it ever becomes an issue both items could be tuned. Murder Cap's proc should deal more burst damage than a Focus Hat fully stacked ability.

Both items sharing a named Unique Passive prevents them to be used in conjunction, that way forcing mages to make a decision on how they want to scale, instead of just getting +35% AP.