Zed vs Swain

To kill, cast Death Mark (R), then Living Shadow (W), Shadow Slash (E) and Razor Shuriken (Q): with two shadows, you throw three shurikens.

Cast Death Mark (R) just as the enemy casts their decisive spell: during the dash, you're untargetable.

After Death Mark (R), save the recast to get out: you swap places with the shadow left at your starting point, far from the fight.

Save enough energy for a full combo rather than casting your spells for nothing: Living Shadow (W) refunds energy when you and your shadow hit the same target.

In teamfights, go around the sides and save Death Mark (R) for an isolated target: going in from the front exposes you to the whole team's CC.

Get out of the Nevermove (E) path as it comes back: it only roots on its return to Swain, then he can pull each rooted champion to him.

Leave the area as soon as Vision of Empire (W) appears: it strikes and slows 1.5 seconds later, and each champion hit gives him a Soul Fragment.

During Demonic Ascension (R), back off and hit from range if you can: he only drains nearby enemies, and his form ends when he stops draining.

If you have Grievous Wounds, apply it during Demonic Ascension (R): the drain heals him every second, and that healing keeps him alive.