Why is teemo banned in one for all

Think about 110 shrooms on the field And 10 seconds of blind if done correctly It's toxic as hell

Let's see, 5 champions with 500 damage traps, perma stealth, stacking. Damage over time, blinds, I think I've said enough

Karthus is also banned.

Both Teemo and Karthus could literally kill an entire team while being on the other side of the map... you could buy items to counter play, but it's pretty toxic.

Karthus' ult over-rides one another. Teemo's mushrooms have a limit meant for only one Teemo. It's impossible to reach normally.