The fact that there is someone else on this earth who also derives pleasure from Ilya's domming is a miraculous bonus, a wowwow you think this will be enough pot of gold at the end of the da, just like that rainbow. Not that Ilya isn't giving. He is curating the experience and in awe of how much Shane loves doing what Ilya wants him to do, and he's attuned to Shane's responses and pleasure because he cares and he should care, but not because his primary motivation is of service.

Ilya's flint of desire is Shane's bare-faced honesty, how open and earnest and preciously flappable he is, it makes Ilya sick with wanting to devour and debase him. And their chemistry is so explosive not because they can give each other what the other wants, but because they are each so hungry for what the other is already made of.

And I think this is why the Vegas penthouse scene is so misunderstood. Because if Ilya was a service top then his behavior seems so much more intentionally callous. He's taunting, withholding, punishing, and if his True Nature was being of service to Shane's pleasure then his motivations appear selfish and cruel.

But Ilya likes pushing Shane to the point of discomfort, for Ilya's sake. He's self-serving in his sadism, electric with how much it turns him on to make Shane beg and squirm and agree to his 'let's make a deal's and struggle in the challenge of it and then submit to the punishment if he fails ("show off for me, it's my special night." "I won't touch you, but if you get hard...")

Ilya's cruelty is part of their dynamic and it's hot, to both of them, as long as the experience ends with everyone regaining their dignity afterward. This is why so much of Ilya's responsibility to Shane is in the aftercare, a word they would probably never use because their verbal communication skills are far outpaced by their physical communication skills, but Ilya should and does know how to do it (stairwell kissing) and the fact that he didn't do it after Vegas was his mistake. A big one, but not as intentionally selfish as many people make it out to be. It follows then, that Shane and Ilya can repair this rupture far easier than they can for other ones (tuna meltdown) and that by the time they make it to the cottage they can phone call blowjob like they were made for it.