the attraction is there and i do think he likes Ian to a certain degree but it's still pretty low imo. Raymond would still play around and keep Ian as a bed warmer as of now
I think Raymond likes Ian and would do what he can to avoid hurting him. However, his revenge is obviously his number one priority. He's spent years putting it into action and his whole life seems to centered around it. Unfortunately, Ian is a key part of his plan and if ever becomes necessary to hurt Ian for the sake of his revenge I'm sure that as he is now he'd do it without much hesitation.
So I think the answer is yes, he is using him, but in order to use him he doesn't have to go out of his way to be so nice. Raymond does like Ian but it's going to take a lot more time before Ian becomes his number one priority and his revenge becomes second.
i swear i just don't know anymore if raymond actually likes ian or he's just using him. i really hope he's not cuz ian is just so cute and innocent. (づ￣ ³￣)づ