Naafiri vs Rammus

Recast Darkin Daggers (Q) on a target that's already bleeding: the second dagger deals the rest of the bleed plus damage based on their missing health, and heals you.

When your pack has taken hits, cast Eviscerate (E): your packmates come back to you at full health.

Cast The Call of the Pack (W) just before you engage: you're briefly untargetable, your pack grows, and you gain AD and move speed.

Push your wave, then roam toward an isolated champion: with Hounds' Pursuit (R), you and your pack dash onto them, and a takedown lets you recast it.

Stay behind your minions: Powerball (Q) stops on the first enemy it collides with, minions included.

If you deal magic damage, lean on it in trades when Defensive Ball Curl (W) is on cooldown: without it, his resistances drop to those of an ordinary tank.

If you're ranged, don't let him reach melee range when Frenzying Taunt (E) is ready: its range is short, and it forces you to attack him.

Get out of the Soaring Slam (R) area fast: aftershocks repeat the slow there, and if cast during Powerball (Q), it adds a knock-up in the center.

Don't attack during Defensive Ball Curl (W): each auto returns magic damage to you, and he gains armor and magic resist.