The whole idea behind this guide is that with season 4 assists are worth more and the new GP10 items give you more gold that ever before. This allows swain to be extremely effective in the bot lane with his high base damage thanks to his E and massive amount of soft CC thanks to his W and Q which allow him to make ganking his lane super easy. Additionally once swain hits 6 he becomes the perfect tank support with all of your sustain and damage you can win almost any engage. Finally he becomes a late game monster so even if your adc sucks (don't steal their farm in laneing phase) you can carry them in the late game.