[Nanya01]

Could just be like, as you said, Keroko, a Belkan Rare Skill but the translators screwed it up.

After all, I'm pretty sure that Carim and Verossa both inherited their skills from their ancestors.

Which would be why Jail cloned Nove from Quint (or Subaru, not certain, I think from Quint myself, though considering that Subaru's a clone of Quint, it doesn't matter, huh?), he wanted the skill that's passed on from parent to child and then helped Nove out with her own unique I.S.

After all, Sein admitted her I.S. was a mutation.

And, as we've seen with Otto and Deed, just because you're related doesn't mean you'll get the same I.S.