Ideas for Teemo Changes
No champion should be so powerful that an item is invented solely to counter them. Teemo has two, the Lightbringer and the Sweeper. Even those are useless if Teemo simply places the mushroom on the edge of the brush. Teemos build ALWAYS includes Sorcs and Liandrys, and usually Rabadons and Void Staff, most likely with Nashors, leading to a very stale and inflexible meta.
Outside of these two items, there is nothing you can do to stop Teemo from tossing a mushroom down every 30 to 16 seconds, and having that area become a 10 minute death trap.
First, reduce the duration. I say 3 minutes. Still gives a long enough duration if he's using them defensively to stock more, and offensively requires forward planning.
Second, remove the slow. It's kind of pointless when an ADC or Mage is going to lose a third of their health to it anyway, especially if you're halfway across the map and unable to even make use of it. This should also reduce the power of Liandrys, making it less of a must-have and merely a strong option.
Third, make them visible if placed in the open. There's no reason you shouldn't see the Yordle-sized mushroom sitting in the middle of lane. In the brush, however, long grass would make it much harder to see.
These changes should prevent Teemo from controlling the entire map with minimal interaction with the enemy team.
