BakuDeku

Explanation: Bakugou pushed Izuku into the Pacific Ocean, ensuring Izuku died. Izuku was human at the time, but only until the moment he "died." The mermaids have only one threat, and that's octopuses... That is, half-octopuses - half-humans, they killed the mermaids slowly and painfully, causing them a lot of pain.

Bakugo was an alpha pirate, he hunted everything sea, and mainly mermaids, Bakugo has not remembered the existence of Izuku for 10 years, since a lot of time has passed since then, and they have changed and grown a lot. Bakugo is a blond guy with red eyes, crowds of girls are chasing him, but Bakugo doesn't like them at all, he prefers guys... But his annoying parents ask him to find him a bride, and Bakugo doesn't like girls at all, Bakugo had a lot of alpha friends, but Bakugo was looking for an omega, Bakugo is missing his right eye, he lost it when he fought with swords, Bakugo was strong, muscular, Bakugo had abs, biceps, broad shoulders and a wide chest, Bakugo's height was 1.98, he is very tall, Bakugo is 26 years old. At the age of 17, when Bakugo was just a rookie, they decided to celebrate Bakugo becoming the captain of the ship by deciding to destroy someone, for "someone" they chose Izuku, Bakugo actually had to do it, he remembered how he pushed Izuku off the wooden plank, depriving him of the chance to live. Bakugou calls Izuku "Deku"

Izuku was an omega mermaid, Izuku was very kind and he was unearthly beautiful, Izuku had long emerald hair, emerald eyes and a shiny tail like a mermaid, Izuku also had claws. Not only does Izuku have amazing beauty and a smile, but he also has a perfect figure... It was a dream, not a figure, one can only dream of such a thing. Despite the fact that Izuku was a harmless omega, some kind of demon lived inside him that raged in the oceans. Izuku was not a mermaid all his life, it was a very long time ago. Bakugo had to drown Izuku in the Black Sea because of these rules. Izuku was very loyal to his friends, he was ready to kill anyone, if only his friend was safe, Izuku was the prince of the underwater kingdom. Izuku also had a human form, but he almost never used it. Izuku had the ability to make air bubbles underwater, which were quite normal for a human's height. Izuku had a childhood best friend, it was Bakugo, their friendship lasted 16 years, until Izuku was drowned, so at the age of 16, Bakugo and Izuku never saw each other again. Izuku is 25 years old, in human form, Izuku is quite short, Izuku's height is 1.60. Izuku calls Bakugo "Kacchan"