There's a reason why Janna is so hard to balance
There's been a lot of hate for Janna lately (I myself admit to this), but it's for the wrong reasons. People say it's the current itemization that's causing problems. But even without all the broken support items (ancient coin before the nerfs, ardent censer, redemption, etc), Janna was still a problematic champ. Yes she is a ball of stats, but the real problem is that her cc abilities have no channel time and are almost all targeted abilities (almost no skillshots). With her 'q' she can instantly knockup anyone who gets close to her or her allies, and no matter how you look at it a knockup is very powerful cc. You can nerf her damage and her items all you want, but as long as she has access to numerous cc abilities with no channel times she will always be a problem.