I win this all the time.
Get level 3 SF, harras with a revolver. You get sustain and money, and shut teemo. When your Q gets to 2 second cooldown with items, you can get it to 200 in 5 minutes.
Also, call your jungler. Teemo explodes when he is Withered and ganked.
EDIT: revolver on nasus is NOT a viable build in any other case, but it helps in this one!
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