Incoming worry: will AP mages in bot get soft-countered by enchanters building athene's?
I'm not saying it's a definitive issue, but it's got to be on the radar.
There's no way chalice of harmony isn't the right buy into a lane like Ryze/Lulu, Vlad/Soraka, etc. Then you end up with it causing some of the same problems it caused when it was an item for AP mids. = /