Swain, The Cane, and The Leg
I see a lot of posts regarding the matter of Swain lacking his memorable walking cane post-rework.
While most of you already know that he's got a cane in one of his emotes, his dance to be exact, apparently there's a detail you missed.
Look at his right leg for a second, then compare it to his left one. That's right, the armor plating and structure is different. There's a supportive plate formation that circles around his ankle, and another one further upwards - around his kneecap.
What does this mean? It is highly likely that while Swain isn't actively bearing a cane for walking anymore, he HAS IN FACT sustained damage to his leg. Specifically to his achilles heel and ham's muscle tendons. This means he's unable to move or bend his leg in an ordinary fashion because his instep will drag behind, failing to stick to a 90 degree angle without proper support. It's also more than likely that he won't be able to bend his knee for similar reasons, leaving him "peg-legged" for good.
It could be a prosthesis, but from a visual standpoint, that seems unlikely. Why ditch the cane, you ask? Because the grand general of Noxus - a nation that despises weakness - would hardly be willing to openly showcase his vulnerability. His dance would hint at him resorting to a cane outside active duty, though.
Hope this clears things up.