User blog comment:Bashfrog/Sion Invisibility Syndrome/@comment-5035765-20130728234151

Sion is basically in the same place Karma used to be... a kit that disagrees with itself

thus, RIOT has stated many times that they are working on pretty much a complete rework for him which will likely focus him onto the AD bruiser position he was originally intended to fill. Morello has been saying on his twitter that it's been really hard to make him work in a way that will feel familiar to longtime Sion players, though, which is why it's taking SO DAMN LONG (same for Hummerdonger)

So this blog really just pointed out a known, longstanding issue.