So, that rageblade rework

I am just going to ignore the attack speed portion, as I do not care about it.

4 ap every time you cast a spell, stacking infinitely.

Jumps around the jungle, stacking up AP by hopping and swiping in cougar form. With how low her cooldowns are (and cougar form having no cost), she can easily build up hundreds of AP if she can avoid direct conflict. Needless to say, having several hundred AP available to you with one item makes your ganks a bit devastating if you land a spear.

THE KING OF THE FOUNTAIN IS BACK!!! Farm until you have enough for this item, then spam Q in base and have your jungler head mid. With the potential to stack up AP from this faster than even nidalee, you can rake in the gold with 600 AP requiems at 15 minutes in. Ban kindred and build CDR to force the enemy to build zhonyas. Yes, Cait, I am talking to you. (for some exact numbers, Karthus Q has a 1 second cooldown, allowing for 4 ap per second or 240 AP per minute. If you sit in base doing this for a mere 5 minutes, you can requiem for 250(+60% of ~1250)= 750 damage to everything. Imagine level 16, you have been spamming for 20 minutes straight. Your right hand is cramping, yes, but you now have AT LEAST 4840 ability power, even if you have ZERO ap from runes, masteries, or other items. Ult will deal 3430 damage.)

Just make sure you take the empowered recall mastery. You need to cast spells every 8 seconds, and recall normally LASTS 8 seconds. The 1 second reduction allows you to cast a spell after the recall completes to avoid losing stacks.