User blog comment:Paul.rea/The Destroyer of Worlds: Dissecting Deucalion/@comment-28037703-20160324004448/@comment-4723271-20160324012518

Alpha of alphas, apex of apex predators,  death destroyer of worlds, all of these are just nicknames he gave himself, it's a product of his huge ego. As for his alpha form, this isn't canon but I've always assumed his form was a reflection of the type of person he is.