I like the corruptions in Horror Adventures, but one thing that bothers me is that vampirism corruption has the Fangs manifestation, and that manifestation gives the character with the vampirism corruption the ability to grow fangs as a swift action. Those fangs can then be used as a primary natural bite attack that deals 1d6 piercing damage for medium creatures, 1d4 piercing damage for small creatures. The fangs can also be used so the character with the vampirism corruption can make blood drain attacks against helpless or pinned targets.
However, actual vampires, built with the vampire template, do not have a bite attack. They have fangs, of course, but they're only used to make blood drain attacks while grappling, not to make bite attacks.
So is it a problem if I just give my game's vampire template the ability to manifest a bite attack as a swift action that functions like the bite attack from the vampirism corruption? Vampires already have a primary slam attack that deals energy drain, so I figure a couple reasons they might not use their bite attack are 1.) It requires a swift action to manifest, and 2.) it doesn't do energy drain like their slam attack.
I've also considered nerfing the vampirism corruption fangs so they're a secondary natural attack instead of a primary natural attack, then giving it to the vampire template, but I don't know if that would hurt the vampirism corruption too much. if it's changed to a secondary attack, will it negatively impact the vampirism corruption's ability to drain blood? That's a CMB action, so I'm not sure if the attack penalty of the secondary attack comes into play.