Swain is an odd champion, half his kit is good against ranged, and the other half melee. He gets pretty tanky throughout the game due to his vast itemization and passive max health gain. He is ranged ofc so he is very easily capable of poking down most top laners before going all in with ult. You out-sustain and out-heal most of them in combat so as long as you have HP advantage and punish them early with Q and E harassing most if not all matchups should be winnable.

I included notes for everything! Every spell combo, runes, items, and whatnot. I really didn't feel the need to include notes for threats and synergies, it's all pretty self-explanatory. Playing Swain top has a lot more relaxing/easier matchups that you don't need to do your best faker impression to beat.

Every matchup really does boil down to harassing the enemy laner and spacing correctly, I guess that could be said about a lot of things though. Top lane is a lot easier than mid.

The synergies I listed are champions that will likely be ganking your lane. The best supports and junglers that could come and visit you up in the lonely island of top lane.
Theres too many champions to list his best synergies with. The just of it is he likes to fight with people who apply a lot of crowd control.

The basic bread and butter combo. E -> W -> E2 -> Q -> AA
Landing E allows you to have enough time to throw out a W, as the root is ending you want to recast E to pull them closer to the center of it to ensure W hits. Practically impossible to get out of after pull unless they dash or blink. Follow up with a Q and AA if you can.

Walk with E. Throw out your E and walk to the side to try to increase its odds of hitting.

Activate Ult and recast ult for the slow to make E easier to land.

E-Extend, when the enemy laner is in the minion wave you can throw E out to hit the wave and hopefully, the laner will be in the explosion radius. You can use this to get a little extra range on your E.

You don't necessarily NEED to level W at lvl 3, put 2 points in Q early for a little extra oomph in your fighting capabilities. The reasoning behind this is because you will likely NEVER land W 1 on 1 without landing E first and since that ability is dookie dog **** Q will be much better to put a point on that early on.

Always use W to scout out enemy JG, and look at their camps, grubs, or the rift herald.
Keep an eye out for any skirmishes or duels in the midlane, there is no reason not to try to assist allies with W, you get free gold(if they kill) and free passive stacks.

Any time enemy laners walk up for minions you want to Q or E harass, make them earn that ****. Especially if they are scaling champs, DO NOT LET THEM FARM FOR FREE.

Remember Swain loves to team fight so try to contest grubs, not many champions have enough damage to burst through his HP at level 6. Especially these weaker tank top laners.

I learned everything through experience and guides. I would not be where I am today (league-wise) without the YouTube channel HusumLol. He is the GOAT of Swain players and is an incredible player. He uploads and streams every day alternatingly. He knows so much more than I ever would so be sure to check him out.