Have fun with them! Kinda puts it in perspective just how much of a weirdo he is, having all that power and still doing 99% of all his work by hand...
By the way, I don't know if the characters receiving the powers would intuitively know from whom they came (or if they could figure it out by sheer process of elimination), but if that's the case, I'm completely okay with Porthos realising they're Sebastian's powers. He's gone long enough kinda-sorta being successful at pretending to be human.