Recharge beacon; Locket / Rod of Ages

I was thinking over a few items and, after reading Meddler's discussion on upcoming Locket changes, I started wondering if there might be alternative ways for supports to provide that 'group aid' feeling. I also was thinking about how Rod of Ages seems like a stat-baton and about how it would be cool if there were a more dynamic benefit to rushing ROA than just getting better stats mid game.

Basically what I came up with was: What if there was an active that created a Zz'rot - like structure designed to provide healing and/or mana regeneration within windowed time frames?

EX: Place a structure with an indefinite life span. This structure builds up charge over time (visible by a secondary resource bar). At 100% charge, the next time an allied champion would enter its range, allied champions within the aura (1100 or so?) are healed for a percentage of their missing health and/or mana over 4 seconds. For each champion beyond the first, the amount restored is reduced by 10%. (Cooldown ~300 seconds)

Regarding Rod of Ages, this could grant a new element of 'rush the item to get as many of these structures down as possible throughout the game'. Regarding Locket, this could provide an interesting way for supports to help their team siege or fend off sieges. Kind of like a bard shrine.

I know this hasn't really been fleshed out that well but let me know what your first impression is.