Nocturne vs Rammus

Fight on the Dusk Trail left by Duskbringer (Q): on it, you gain move speed and AD, and you move through units.

Stay near your target after Unspeakable Horror (E): if the tether holds until the end, they're feared, and you gain move speed toward them.

Cast Shroud of Darkness (W) just before their CC: the barrier blocks the next enemy ability for 1.5 seconds, and a successful block doubles the spell's attack speed bonus.

Cast Paranoia (R) when an enemy is isolated: they can no longer see their allies, and you can launch yourself at them from long range, farther with each rank.

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.