Sett vs Kennen

Start your trades with Knuckle Down (Q): you rush toward your target, and your next two autos deal bonus damage based on their max health.

Cast Haymaker (W) right after taking damage: the stored Grit gives you a shield and extra damage, dealt as true damage in the center of the punch.

Don't back too early at low health: Pit Grit (passive) increases your health regen based on your missing health.

Stand between two enemies before Facebreaker (E): grabbed from both sides, they're stunned, otherwise only slowed.

Grab their tank with The Show Stopper (R) and slam them onto their carries: the damage around the impact depends on the bonus health of the target you grab.

Dodge Thundering Shuriken (Q): each spell that hits you applies Mark of the Storm (passive), and on the third, you're stunned.

Back off as soon as he rushes at you with Lightning Rush (E): it's his engage, often followed by Slicing Maelstrom (R).

When he has Slicing Maelstrom (R), spread out from your allies: the storm hits every enemy around him, and its repeated hits end up stunning.

Wait for Slicing Maelstrom (R) to end before you fight back: during the storm, he gains armor and magic resist, then the spell has a 120-second cooldown.