...and then he asked me to stay onboard as a consultant, to give his paid writer ideas akin to the suggestions I'd already made during the selection process. Then, after I came up with the ideas, his other writer would write them.
I don't blame the creator for wanting to assemble the best team possible, but that kind of arrangement is in no one's best interest.
Why? Because ideas are cheap.
Realizing those ideas to their fullest extent? That's the key.
Do you want proof? Think about how often you mention you're a writer, and someone tries to tell you the idea she has for the novel she's never written.
I could come up with a dozen ideas for this person's graphic novel. A couple of them might even be good. But bear in mind that the other writer is, presumably, a better fit for the project than I -- and therefore also ought to have many of his own ideas for the project. Trying to force the other writer to enact my ideas would be like trying to force the other writer to wear my shoes. They probably won't fit all that well because those ideas resonated with me -- and they might not resonate with the other writer.
What if I want to explore the main character's feelings of guilt and tie them to his relationship to his father? Awesome, right? But the other writer sees the guilt pretty much as a sidecar to the main character, something to be shed and left behind rather than explored. Forcing the other writer to explore it would result in a bored writer and, ultimately, a bored reader.
Picture an idea like the trunk of a tree. You could have two identical trunks, but you won't have identical branches. They won't split off in the same places, won't reach toward the sun in the same way, won't sprout leaves in identical spots. One idea is great, but the micro-ideas are going to give your story its richness, its texture and depth. And micro-ideas only matter inasmuch as they're continuous with the whole.
That's why you can read ten "portal stories" and none are the same, or ten different stories about a young boy finding his destiny and fulfilling a prophecy to save the world. Percy Jackson and Harry Potter have a lot in common -- but they have more not in common.
Moreover, every writer is going to find interest in different facets of the same question. That's why fellow QT blogger Carolyn Kaufman and I both wrote very different fanfiction for Battle of the Planets, using the same characters, the same setup and even based on the same episodes -- but all involving different ideas or different ways of exploring the same ideas.
What about when you go to your beta readers or critique partners and start tossing around ideas for your story? Invariably I'll bet you find your CP makes a suggestion, and most of the time you're going to think, "No, not quite right." But when the CP makes a suggestion that's just right, how do you respond? Not with "Oh, yeah, I'll get right on that" but "OH! And it would be even better if..."
And that's because once you adopt the suggestion, you're going to tint it with all the ideas and all the subtext you brought to your original idea.
Writers often ask if they should copyright their work before querying, afraid an unscrupulous agent or editor might steal their idea. But so what? Your idea should be fully realizable only by you. If an editor wants to try marketing a cheap knockoff of your golden idea, it'll look like a cheap knockoff.
Your story came out of your heart. Your heart is not easily duplicated.
At any rate, I wished the graphic novel team well, and I bowed out. That writer will want to develop his own ideas, and I encourage you too to develop your own ideas. Write your own ideas. Explore your ideas in a way that resonates within the story. No one else will grow your ideas the way you can.