Playing as a villain is a reasonable option - something worth considering is, where does it go from there? If that branch of the story is about descending into inhumanity, what’s the shape of the journey when the inciting evil act is so extreme? Will the draconic blood hunger for increasingly extreme actions, and how will that play out?
(Something I enjoy a lot about A Study in Steampunk is a possible villainous branch which feels both organic and inexorable, and is very effective. It may be worth having a look at that and other games which include villainous/evil paths that work well for you.)
Regardless, please do make the game - it’s easy to talk hypotheticals but that’s nowhere near as useful as seeing how it works in practice.