User blog comment:JuneReil123/Rito, the Clairvoyance... Rito/@comment-12314620-20140520185514/@comment-24606304-20140520194600

"Vision granting skills must inform enemy team that they are in vision."

Wards don't inform the enemy team that they are in vision unless you get sweepers and/or pinks, and its not like there's a beeping indicator to tell you when to place a sweeper or pink because that is where a ward will be...

Not beeing able to know that you are seen by the enemy team is a thing that goes on a lot, I don't see why that should be the reason this version of Clairvoyance wouldn't be good. Of course, there may be other reasons, but the fact that the enemy team wouldn't know they are seen is not it.