Synorigin
When an idea is mostly a known genre skeleton
A premise that is very close to two of the most famous stories in the genre - and a check that said so without softening it.
What was being tested
Whether the check would call this what it plainly is, or soften it - and whether the verdict would stay honest when the honest answer is discouraging.
The idea submitted
What Synorigin returned
Closest matches
- Harry Potter - birthday-triggered revelation, ancient bloodline, a dark lord hunting the family. The same structural spine.
- Star Wars - last of a bloodline carrying inherited power, pursued by an antagonist tied to that lineage. The Skywalker arc almost beat for beat.
- Eragon and the wider YA chosen-one shelf - close to a genre template at this point.
The originality gap
What is derivative is the mechanism of revelation and threat. The antagonist's motive is currently a placeholder - "hunted for generations" is generic evil.
The pivot
Make the bloodline's power something the dark lord needs rather than fears. That flips prophecy-fulfilment into an extraction dynamic, which is a different story shape entirely.
Verdict
About 85% a known genre skeleton as written - the gap above is what would pull it out of Harry Potter and Star Wars territory.
Why this result matters
The two most obvious comparisons were named directly, and the percentage was called high rather than rounded down into something more comfortable. That is the behaviour the tool exists for.
The pivot is also worth reading closely. It does not say "add something original." It changes one specific relationship - what the antagonist wants - and that single change alters the genre the story belongs to.
Sharing a trope is not the same as copying. Every one of these matches shares tropes with hundreds of other books. What makes this premise derivative is that the tropes arrive in the same arrangement, which is a structural fact rather than a judgement about the writer.