Offering power by dangling the dream person as a reward? Reward for what? That doesn’t make any sense.
But if your character isn’t interested or doesn’t trust the dream seducer then denying them is an option, so what’s the problem?
Exactly!
There's some interesting snark if you get the dreams then rebuff the 'Dream Lover' tm. It's a Role Playing Game. If your character isn't easily seduced by a pretty face, Role Play it!!!
The problem is that - as far as I understand - that's strongly tied to a custom character's personal quest AND "the dark side". So if your character isn't easily seduced by a pretty face, you lose a huge(?) chunk of story. A story that isn't necessarily a romance subplot. If it was just a customizable romance option and rejecting it would only lock you out of the romance, fine, whatever, I don't care (just give me the option to not make the dream waifu at the beginning). But the way it's implemented now appears to conflate "seductability" with leaning towards abusing tadpole powers.
