Ok this is something that has REALLY been annoying the hell outta me ever since I saw these art works getting uploaded to Danbooru. Why are they all tagged with "corruption"? Link putting on the Fierce Deity mask doesn't turn him evil, it just transforms him into this super powerful form, like going Super Saiyan in Dragon Ball. There's no info stated anywhere that the Fierce Deity is evil. It's just the same as Link's other masks. It transforms him and gives him special abilities, and that's it.