User blog comment:Elphrihaim/Clarivoyance...?/@comment-4958877-20130807134543

could have been converted to tree of of Trent from Dota:

ward CD 4min, life 1hp, enemy can  which can be seen if the enemy to come close to it.

Features: sees the other wards (it can be used as pink); the time of life is infinitely.

as a variant: installation range 0 (put at the point where you are now)