Zilean vs Swain

Place Time Bomb (Q), reset it with Rewind (W), then place the second one on the same target: the first explodes instantly and stuns enemies around it.

Cast Time Warp (E) on the ally who needs to catch up or escape, or on the enemy to slow: the same spell does both.

Place Chronoshift (R) on your carry right before they die: too early and the enemy switches targets, and if they die with the rune, they revive after a stasis.

Give the Time In A Bottle (passive) experience to an ally who is close to leveling up: you receive as much as you give.

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.