Count Dracula

Ai, like Yuuki, would be impossible to hypnotize as it is also something she can do. She'd also offer blood if he needed it, though would be more likely to point him to the clinic where blood is offered (because she can be fussy sometimes) and has a protective family who wouldn't like it. Also all the blood stuff that applies to Yuuki, applies to Ai too since Yuuki is Ai's birth mother.

Soushi (festumborn) will be harder to manipulate with hypnosis as he has pretty good mental shields and getting into his head will be extremely difficult. I'd be okay with feeding (not that Soushi would offer willingly) but his blood would probably taste strange considering he's not entirely human.

Velvet (oligomania) has no mental shields so hypnosis is possible - but she'll be pissed and violent afterwards so that's a thing. Also available to feed from but again, not human - she's a demon so it might taste off.