Hello and welcome to my Swain guide. I have been using Swain for awhile and i belive him to be my favorite Noxian. I have just a few tips to share and that's it the explanation isn't required for those of you who don't care about the words just the build.

The masteries are made so that you can excell at early game spell punishing. Early game Torment ability leaks chunks of life away at the cost of very little mana. On top of that you can sit there and spam it, then last hit minions all the way to full mana with Carrion Renewal.
When playing these masteries however you must be aware that until Ravenous Flock is available or you have built a health item such as Rod of Ages, you will be very squishy. Be aware for early level ganks. be sure to leave Nevermove on hand for securing a combo or escaping a bad situation.

The item list involves all the essential items to being an efficent Swain. Swain is built as a character who can regenerate his life rapidly while putting out a steady amount of damage with his ultimate Ravenous Flock. the rest of his abilities are built on the cc and overall damage delt. What i mean is that Swain is good at putiing out damage but he requires to survive until the damage has succeeded or he will simply die so health is also required. Liandry's Torment is a good way to extend upon the overall damage over time effect as well as stacking magic penetration which is extremely important to Swain as he is easy to counter with a magic resist character Volibear Garen Kassadin. Beware of burst damage and silences! Even zonyas hourglass wont save you.

Nevermove is mainly for the snag less for the damage, and Torment extends your attack damage as well as dealing more reliable damage to the enemy champions. So in my oppinion Torment should always max first followed by Decrepify.

Swain is not great at ability farming with Decrepify or Torment so it is best to use a quick Ravenous Flock and a lvled nevermove for farming. Otherwise you must rely on last hitting them. ( big reason people dont play with Swain. hard to farm with around teammates unless they choose to give you minion kills.

If you are someone who needs a character that can just sit in lane forever and ever, but also move around the map without hinder or assistance I suggest using this build. when banshees veil is built you can imediatly start entering fights with large portions of health, mana and an ability block just so you know that )a you will be able to ultimate period-no interrupts.
b) any characters relying on a burst from an abilty or that has lane traps ( Teemo, Caitlyn). The rest Of the build is self explanatory, Spirit Visage will raise Ravenous Flock heal rate, [will of the ancients]] will increase it more so, and all the while your health and mana rate are stacking. Once you cant die your enemies will cry. Simple truth.

I find that once knowing the basics of Swain anybody can teach you "how to play league" but if you dont know Swain this is what you need unless you need more help in wich case you should find another guide, but dont be scared to still keep my build in mind. Thank you for checking it out hope it helped.