Jayce vs Nasus

In cannon form, fire Shock Blast (Q) through Acceleration Gate (E) from the start of lane: the orb gains speed, range and damage, and it's your best poke.

To all-in, switch to hammer: leap in with To the Skies! (Q), activate Lightning Field (W), then knock your target back with Thundering Blow (E).

Land an auto after each weapon swap: switching to Mercury Cannon (R) reduces your target's armor and magic resist, and your first hammer hit deals bonus magic damage.

To escape, swap weapons then walk through Acceleration Gate (E): Hextech Capacitor (passive) and the gate each give you move speed.

Early on, take a trade whenever he steps up to last-hit a minion: each kill with Siphoning Strike (Q) increases its damage for the whole game.

Freeze the wave near your tower: to farm with Siphoning Strike (Q), he then has to step up and expose himself to ganks.

Once he hits level 6, don't engage during Fury of the Sands (R): for 15 seconds, he gains health and resistances, and his area damage scales with your max health.

In teamfights, if you're ranged, hit him while backing off: he has no dash, only Wither (W), a slow that grows stronger over time.