Sylas vs Swain

Weave an auto after each spell: Petricite Burst (passive) turns it into a chain swing around you, with bonus magic damage.

Save Kingslayer (W) to finish or to save yourself when your health drops: its healing grows with your missing health.

To engage, cast Abscond (E), then recast within 3.5 seconds: Abduct (E) pulls you to the first enemy hit and knocks them into the air.

Cast Hijack (R) on the enemy whose ult can turn a teamfight: you keep a copy of it, cast with your own stats.

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.