Idea for a down-scaling item

So I've been a fan of Rod of Ages for a loooong time, but it's always puzzled me why it's so rarely seen for being so cost-efficient. Every time I see people discuss the matter, the answer is always the same: "People don't want to wait 10 minutes for their power spike, they want it right now." While listening to the Trinity Force Podcast (#shamelessplug) talk about it and come to the same conclusion, I mused to myself, "Well what if it worked the other way around?" And then it hit me. Think of the Sanrei Glove from Bleach. When a Quincy trained with it, they were able to reach a high level of power. If they took it off, they would activate Letzt Stil (Last Style) where their power would shoot through the roof and they'd become an almost unstoppable force for a few minutes, but after that their power would rapidly deteriorate until it vanished completely.

What if there was an item that granted a massive power boost immediately, but depreciated over time? Kind of like Sword of the Divine now, but on a more long-term basis. Of course if it were strictly like RoA but with the stacks working in reverse, I'd imagine horribly fed champs would simply buy one and sell it once it started to fall off and then buy another to sustain their power and it would basically turn into "League of Reverse-RoA's" but what if it weren't that simple? What if it permanently debuffed the user and didn't allow for them to simply buy another one to counteract it?

Extreme example: Sanrei Glove (UNIQUE) costs 4000g (2 Needlessly Large Rods+800g) and gives +200 AP, +25 Mana Regen/5, +30% CDR, and +10% Movement Speed for 5 minutes. After 5 minutes has passed (or immediately if the item is sold), the item and its stats disappear and the user has a permanent debuff of -35% AP, -10 Mana Regen/5, -10 % CDR, and -5% Movement Speed. This item can only be purchased once.

Granted this is completely and totally unbalanced with these numbers, but the idea is there. Doesn't necessarily have to be for AP champions, but I can most likely see champions like Leblanc or Katarina going for a concept like this as early-mid game are generally when they're at their scariest. Thoughts?

EDIT: After thinking it through a little more, I've thought of several ways an item like this could be used: 1. That burst mage that knows they're going to fall off in a few minutes anyway or, bought later in the game, allows them to stay relevant past 30 minutes 2. That support Janna/Nami/Taric that wants to be able to do respectable damage in a key teamfight 3. That utility mid laner like Ori that can become a 2nd support and easily bring something to the table despite the debuff.