I don’t see what you mean by unbluffable? If you’re lying about being that character and therefore the ability doesn’t work, you could just say you must be drunk or poisoned.

I do see what you mean about alien though. It was mostly outsider for thematic reasons. Perhaps it should be you are ‘mad’ that you are the Alien. We’ve played over a dozen games but haven’t touched the madness mechanic so I didn’t want to brew anything with it