Rain had imagined that some of the mermaids of the Seafolk possessed an intriguing talent: the ability to induce a state of brainwashing in their targets through the enchanting allure of their voices. However, this ability posed certain challenges when utilized in combat.
The effect of their voices had a relatively short reach, necessitating that the mermaids venture dangerously close to their intended subjects. This proximity put them in harm's way.
While employing their captivating voices, mermaids were unable to perform any other combat-related actions. This meant they couldn't attack, defend, or provide alternate support to their allies. This one-track approach made them vulnerable during the process; they couldn't move either.
Rain didn't ask that, but it seemed that Seadir had a big mouth and that was most likely one of the reasons why he wasn't at the top of the hierarchy when it comes to the sea emperor kids.