[ Subaru tilts his head curiously, frowning in thought. Had he not said he was born this way? There are so many questions, he's not entirely too certain. ]

Vampires can be created, there isn't any soul-trading involved.

[ Fai had, in fact, kept his soul. All it required was the blood of a born vampire, but knowing how Kamui would feel about such disclosures, he keeps this to himself. ]

As for me, I was born this way along with my brother. [ Twins... ] So I'd have to agree the idea of missing something essential is strange.