I was referring to your suggestion about gaining the power from the dreams rather than a dialogue choice, may have misunderstood this. If there was another entity involved, the dream person would be extra incentive to get you to go the power route, so in a sense, they would be a reward. Kind of like how crime lords get the nice cars and the hot girls. Having this done by a separate entity would also allow for more headcanon of what the dream person means to you.
I’m not sure how having a unnecessary 3rd party offer the person you dream of to you allows for more varied plausible relationships.
“Unlock your powers and I will give you your friend / sibling / whatever but only in your dreams” is weird. The point of the Dreamed (which I will now be using as a shorthand for the one you dream of) is to seduce you with power. I don’t see why this requires a second entity to be manifested in your mind.
I’m all for headcanoning the hell out of RPGs, but why you would apparently headcanon that the Dreamed is anything other than an object of potential romantic desire for your character when that’s pretty clear what they are intended to be seems strange to me. It would be like headcanoning a backstory for Sarevok as soon as you meet him in BG1 and then getting annoyed when you find out his actual background doesn’t match this.
