User blog comment:JuneReil123/Rito, the Clairvoyance... Rito/@comment-12314620-20140520185514

I'm sorry to say this but as some people have already pointed out vision granting skills must inform enemy team that they are in vision. For example creating traps for enemy team is currently difficult to pull of since it often requires lots of coordination as well as some luck for trap to succeed. This CV change would pretty much say to a team that if your opponent has 1 player running CV you should never try to set up a trap, especially as a team, since you might have just gotten CV:d and are in for a terrible teamfight. Another aspect to account for here is tracking summoner spell cooldowns. Every single summoner spell currently in game has a distinct visual effect. In higher level of play most people communicate in summoner cooldowns letting their team know what summoners your opposing laner has up. Your clairvoyance would be impossible to track.

Clairvoyance might need some love but I honestly don't think that quaranteed success is the right way to go. Charge system with minor cooldown between activations might be nice (2-3 CV charges which could be stored). Not every summoner spell has to be super good at every elo (Clarity, Ghost is situational and used only on a few champions, low elo Cleanse).