That's true. As far as sacrifices go, I guess blood would be the most efficient one out of the all the not-efficient options.

[ not that flat would really understand. sacrifices have never been a necessity for him in his spell work.

but inefficiency aside, subaru's story makes the light in flat's eyes shine brighter as he leans forward with very visible excitement. ]

Oh, but that's cool! An adventurer vampire-- you really can't get bored with eternal life when there's so many new worlds to see and people to meet! You must have awesome stories!