Miss Black Dragon doesn't want to be a mount

The boy, who was born sickly, eventually did not live to adulthood. Before he died, he made a desperate wish that if there was an afterlife, he must have a strong body.
When he regained consciousness, he had turned into a black dragon egg.
His wish was indeed fulfilled, but the egg was female, well...
never mind!
Miss Black Dragon believes herself to be invincible, but fate makes her meet her nemesis, a brave girl who dreams of becoming a great knight.
Oh no, now the girl wants to become a great dragon knight.
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