Idea for Teemo Ult Change

Let Teemo be able to purchase an item in the shop for free called a "Danger Sign", that goes in the trinket slot and is replaced by whatever ward you were using after placed. He can only have one sign on the map. When placed, the sign makes all nearby shrooms in sight radius of the sign be immune to being revealed by sweepers or wards. Standing on the sign for 1 second will destroy it, like a Rek'Sai Tunnel. The sign is visible in brush, and shrooms cannot be placed within a 200 radius of the sign. It does not give vision. The sign disappears after 1 and a half minutes. When the sign is destroyed, all mushrooms are revealed and disabled for 2 seconds.

The idea, kind of borrowed from dota but not really, is that the sign tells the enemy that shrooms are nearby, but doesn't tell enemies where they are. This can lead to serious mind gaming in lane where you drop a sign but no shrooms, and the enemy is scared to pass. This ability also gives Teemo counterplay but keeps him still decent,as his shrooms cannot be disabled instantly by a sweeper. However in a fight a player can quickly destroy the sign and then disable all of Teemo's mushrooms. Teemo can also use this sign in tandem with his passive, to suprise and kill enemies with it. All in all the sign is a strong idea for counterplay as it forces Teemo to play smart with it, while still giving him the power to bait enemies with his shrooms. However his opponents can still counter the mushrooms by jumping onto it and destroying it.