As for why not use magic attacks and acidic breath, there must be an opportunity to use them.
As a member of the true dragons, the Black Dragon naturally has a magic talent, but it is limited to poison and corrosion types of magic, and Hephaestus is faster in flight than it.
Hephaestus's mad biting makes it hard for the Black Dragon to find the right moment for a magical counterattack, so it might as well rely on its physical instincts to fight back.
Logically speaking, when two Giant Dragons fight physically, even if there is a power gap, they can last more than two minutes, after all, the physical quality of a Giant Dragon is excellent, and they can recover quickly even when injured.
But unfortunately, the first Green Dragon was too disappointing and died prematurely without holding up long enough.
This allowed the first Bigby's Hand that dealt with the Green Dragon to be freed.
And it became the final straw that broke the young Black Dragon.
