You'd need some strong magic mumbo-jumbo bounded fields or stuff to hold a Servant prisoner anyhow, given they can become immaterial by shifting into spirit form.
Yeah, exactly. And, an anti-magic field would cut her off from her prana supply, which means you'd need another way to give her prana. Plus, even then I think it'd be difficult to do anything more than contain her, since any attempt to interact with her would allow her to fight back (you couldn't use anti-magic devices on her because she is literally
made of magic, and thus would die if you did).
Like I said, Satoshi only managed to hold her prisoner because she wanted him to. I don't think he even used reinforced ropes etc., so she could have trivially broken out.
Yolf the point was possible versus impossible.
and as I have said and demonstrated with names and mike I'm willing to work out events and go with the flow when I am asked so Satoshi can be kidnapped easier than you think
As I said, I can't see how Bloble could do it, though. I don't get the impression that his character is overly strong (he needed to get help just to kidnap a generic vampire mook, and I'm pretty sure Satoshi could defeat one of those without even breaking a sweat), and nor does he have any allies on Satoshi's level.