Had that been all, the Merfolk Tribe would not have sent out a Bloodfish distress call. What drove them to despair was that, immediately after establishing the Sea-Cliff Alliance, Lei Tingyu turned his sword on them and demanded they surrender their legendary secret vault.
The Merfolk Tribe's secret vault was itself only a legend, dating back untold tens of thousands of years. They had no way to surrender it, so Lei Tingyu led the Sea-Cliff Alliance in slaughtering them.
The Merfolk Tribe had originally had nothing to fear from the Sea-Cliff Alliance, but Lei Tingyu had previously stolen their secrets and gained control of the Nine Dragons Token, as well as stealing the treasures they used in battle. On top of that, he had used his identity as a descendant of the Thunder Ancestor to win over and buy off other members of the Water Race. As one side waned and the other waxed, the Merfolk Tribe suffered defeat after defeat and now faced extinction.
Thus, in their Bloodfish distress call, the Merfolk Tribe had sworn a Blood Oath: if the Dragon Race saved them, they would submit to the Dragon Race forever and willingly hand over all their greatest treasures, including the Nine Dragons Token and the secret vault.
The main reason Fang Yun had accepted the Bloodfish distress call ahead of the Four Seas Dragon Palaces was the Nine Dragons Token.
The Four Seas Dragon Clan had inherited only part of the Dragon Race's legacy, and much of its ancient knowledge had already been lost.
The present-day Dragon Race no longer knew the Merfolk Tribe's origins. They knew only that the merfolk revered the Ancestral Dragon as their master and could loosely be considered part of the same Water Race family.
Fang Yun had not originally understood the