Teemo

If u play vs Teemo just pray. Thats one of the hardest matchups. Simply dont die and play safe thats all u can do just to be worth in team fights

Ambessa

Her moves can be a bit annoying but you can take advantage of the fact that they have a long cooldown, so wait until she uses up each skill and try to land a W.

Briar

She is not a big problem play safe in early build one or 2 items and u should be stronger then her. Use W when it is maxed.

Illaoi

Play crit vs Her if u are good sett and if u are not play safe and Tank

Aatrox

I think Aatrox can be both an easy and a difficult opponent for Sett. Try to use W well, and at first, if you see he's good, don't engage him, but when you see he's not very good at Aatrox, engage him.

Malphite