I will keep updating this guide throughout my own process with matchups, items and runes

Phase rush is a great choice for Swain in lane and on teamfights. You can trade fast with a
combo and get away with the bonus ms. You will also get some useful secondary runes in the sorcery tree


Conqueror also suits Swain good, but keep in mind that you got basically no useful runes in laning phase if you go for it. Its hard to stack it in the early game and nearly useless at trading in lane. Pick Conquerer if the enemies got multiple tanks or you already know that the teamfights last long.

Early game

The early game is just about getting as much stacks as possible. Most of the time you wont be able to solo kill the enemy laner. Wait for the jungler to get a safe stun on your enemy.

Mid Game

In the early game you should have enough items and souls to be really useful. Go for objectives and try to get impact all around the map with the . You can tank most of the damage easily if you dont get oneshot at the beginning in the fight.
Get some squishies with your and try to zone the enemies as much as possible with the

Late Game

The late game is pretty similar to the mid game. Your job is to deal dps in the teamfights and tank their dps. Now the enemies might got some antiheal which you should keep in mind

For the secondary runes you got some variants in the resolve tree.

Conditioning

Conditioning grants you some more base tankyness. This is one of basic secondary runes in combination with . Take it if you think you need some more base tankyness to survive their burst.

Second Wind

Second wind is a great choice in combination with . Take it if you think you can easily survive their burst.

Bone Plating

Good choice against assassins like

Overgrowth

Also one of the basic runes for more base stats

Revitalize

More heal