Some of you villains out there are crazy cultists and I guess that’s a valid lifestyle choice, even if your motives make no sense whatsoever and you don’t even seem like a real person anymore.
Some of you, however, should know better. If you’re up against the protagonist concerning an ancient prison filled with ancient eldritch horrors or unspeakable evils, you’re no longer the Big Bad. You might be the main villain, in some form, but you’re not the Big Bad – that’s whatever’s in the prison that will devour you quickly as thanks for releasing it – if you’re lucky. (If you’re extremely lucky, extremely, extremely lucky, you might not die at all).