Karma vs Swain

Hit the enemy with your spells: Gathering Fire (passive) lowers the cooldown of Mantra (R) with each damaging ability.

To poke, cast Mantra (R) then Inner Flame (Q) at a group: the explosion leaves a ring of fire that slows and deals more damage.

At low health, cast Mantra (R) then Focused Resolve (W): you restore part of your missing health at the start and end of the tether, and the root lasts longer.

In teamfights, cast Mantra (R) then Inspire (E) on an ally surrounded by the others: everyone gets a shield and move speed, to engage or to escape.

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.