K'Sante vs Garen

Stack Ntofo Strikes (Q) on minions: after 2 hits, the next cast becomes a shockwave that stuns and pulls, so save it for the champion.

Charge Path Maker (W) when they throw CC at you: while charging, you're Unstoppable and take less damage, then your dash knocks back and stuns.

Cast Footwork (E) toward an ally to protect them or escape: the dash goes much farther, and you both gain a shield.

Knock your target into a wall with All Out (R): they go through it, you follow, and you hit harder at the cost of some of your health and resistances.

Hit him regularly, even with a small poke: Perseverance (passive) only regenerates him if he hasn't taken damage recently.

If you're ranged, kite him: his kit has no dash, and only Decisive Strike (Q) speeds him up and removes his slows.

Wait for the Courage (W) shield to end before your burst: the spell starts with a shield and tenacity, then keeps only a damage reduction.

Once he hits level 6, back instead of staying in lane at low health against him: Demacian Justice (R) deals true damage that grows with your missing health.