OK CLICKBAIT TITLE TO MAKE YOU JOIN HAHA; no but seriously, are they going to make him a Vastaya? I know some of you are thinking "wow but it doesn't say it in his current bio so, no way". Riot changes champion backstories after doing large reworks, so they might throw that entire thing away and make him something like one...or maybe a human who experimented with vastayas and became some psuedo vastaya or something such?
Based on the fact that it was revealed that some Vastyans aided Noxus during the invasion of Ionia (to get a better deal) it is most likely that Rakan's voice line "You were given Vastyan blood but chose to be blind" has some validity and Swain was physically given Vastya blood; possibly having Vlad use it to give swain this power he will most likely have. That, or the line is metaphorical and infers to the blood shed of the Vastyans in the name of Noxus. Don't think that Swain will be a full on Vastyan though.
Taking your idea what if redesign Swain as a Vastaya (druid able to transformn into human form) whos power and domination hunger made him to fight for Noxus and the Black Rose. In my opinion would be original to make the actual transformation inverted.
Demon Swain please, not vastaya.
