When Rain and Seara entered the underwater castle and made their way to the throne room, they were greeted by a large gathering of people. Among them were Seara's siblings, whom Rain had encountered a few times before, but he couldn't possibly remember the names of all thirty or so of them.
In addition to Seara's siblings, the gathering included many nobles from the sea folk. They had all gathered to witness the arrival of the first granddaughter of the sea emperor, which was a significant and joyous occasion in their society.
The presence of Seara's siblings and the sea folk nobles highlighted the importance of this event and the high regard in which the sea emperor's family was held. The atmosphere was likely filled with a sense of celebration and anticipation as they awaited the naming ceremony for Rain and Seara's new daughter.