"Master, I am Wind Dragon Aeolus, and from this day forth, I shall be your sword in the skies!" Aeolus proudly declared, as though it wasn't spouting bullsh*t such as it would rather die than submit earlier.
Upon recognizing Shye as a worthy master, it submitted completely, partly to avoid the excruciating pain the two greatswords would undoubtedly cause.
The agony was unbearable, after all.
Furthermore, while it was considered taboo for dragons to submit to a creature of another race, Aeolus believed it was wiser to do so than to perish in a battle with no hope of victory.
If its kin wished to mock it for submitting to a human, they were welcome to try defeating its master and see if it was a wise choice.
If they were permitted to submit to a superior dragon, why couldn't they yield to a superior being from another race?