I saw someone in the boards complaining about Sett's W deleting him from the teamfight meanwhile the size of it is like Jhin's W, most ez type of skillshots to dodge in the entire game. He even said that Sett is more OP than Zoe which is completely bs. Sett is a carry juggernaut, but he's so basic and ez to counter, some cc and he's dead. + His W is his only source of damage, other abilities do nothing except if you're a tank and your whole team is behind you and you go to 1v1 him. He will just delete your entire team.
How to counter Sett ? Learn to play him, a basic champion like him won't be hard to counter. Dodge his W and you won the fight, I play Sett and if I don't have my W, I'm out sorry. Even tho if the teamfight is mine to control, I need my W. So when you see a Sett uses his W, focus him and the team's carry, and you won! Don't tell me he's OP like Zoe because Zoe was able to Q to kill a squishy enemy + She's a mage