His Innate which deals more damage when unseen.
Does it work like a charge that is consumed?
Does it work if in brush with an enemy ward in it?
Does it work if just i cant see them but they can see me?

Isolated Target
Why does the marker remain for only 2seconds?
What is the range?
Is it active the entire time the enemy is alone?
Do minions or allies remove this passive?

On top of all this, there is no visual effect for his innate and Isolated Target is very subtle then disappears.

http://leagueoflegends.wikia.com/wik...bility_Details

In short, his passive is consumed only when used, not lost when the enemy team sees him. If you're jungling, it's likely that you'll almost always have a charge unless you're ganking.

The only indicator that you have a charge of Unseen Threat is the buff icon over the status bar.

ugh so the wiki finally got updated, it didnt say any of that when i checked yesterday >_>