Riot, you put swain from the middle of all champs to the worst champs in game . he was not even good i dont know what you think is good on swain. I was maining swain and he was not that easy he has no range, bad cooldowns, no mobillity and no wave clear . What you want him to do against any champions ..
Swain is really good in my opinion... Swain top, sometimes mid and if you want the adc to hate you go for support. I've rarely lost a game with SwainHe is quite easy to play. Build a 
and get some 
and upgrade the into an 
. After that, get a 
and get a 
. Then just get 
and maybe a 
... GG
Of course that build may change on wich champion you're playing against, but that's a good model.
