Joules

Full name: Julian Marinero
Age: 16 (splat1), 18(splat2), 23(splat3)
Pronouns: He/him
Gender/Sexuality: butch lesbian
Joules is the captain of my new squidbeak splatoon.
He's in a polyamorous relationship with Del and Mimi, who are agents 4 and 8 respectively, and adoptive older sister to Tulip, who is the new agent 3. He plays on a turf war team with all 3 of them 

story summary
splatoon 1:  
Joules started out as an extremely average inkling. He came from an okay family, wasn't particularly talented at anything, and got mostly C's and B's in school. One day, he was recruited by Captain cuttlefish to help save Inkopolis as agent 3. While down in Octo Canyon, he discovered that he excelled at being an agent. This went to his head, of course, and he began to think of himself as a fearless hero, one who could never lose a battle. Eventually, he was able to make his way to octavio with little effort and return the zapfish. Afterwards, he found that he was still hungry for danger.

splatoon 2:
After the events of splatoon 1 hero mode, Joules craved more missions, so captain cuttlefish told him about the deep sea metro, which he had suspicions about, that there might be something terrible down there. But Cuttlefish was old, and he couldnt do this mission, so he elected that Joules should do it. At some point in time, Joules's communicator got broken and he and the captain were separated, shortly after cuttlefish had gone to investigate an octoling that Joules had knocked out. He became lost in the bowels of the metro for all of 3 months, at which point he created a video journal, which mostly consisted of messages for his girlfriend, Del, who, unknown to him, had gone down to octo valley to look for him. One day, he finally tracked down the captain and his new agent, Mimi, who had become Agent 8, and narrowly saved them from being blended into biomass, but knocked himself out in the process. Afterwards, he and the captain were captured by commander tartar, and joules was to be forcibly mind controlled for tartar's gain, but beforehand, joules somehow convinced the mad AI to give him top surgery through a sort of reverse psychology, which was rapidly healed through some sort of strange goop, but it left strange green scars. (turns out robots arent that smart!). Under tartar's control, he was forced to fight mimi in an epic battle, which ended when the mind control goop was ripped off his face, but his right eye was ripped off as well.
Along with the physical toll, this was a permanent stain on his ego. He, of course, did not blame Mimi for any of this, as she was only defending herself. He realized that he might actually have a sort of adrenaline addiction. he continuously forced himself into more and more dangerous situations, and now he was paying the price. He had to chill out, or he might die.
Back on the surface, he met in the hospital with his girlfriend, Del, who he found out had  joined the NSS as Agent 4 to look for him. There was plenty of tension, of course, since this was the first time they'd seen each other in months. Del had practially become a different person. Instead of the shy girl she was during high school, she had become a brash diva.
About a week after the events of OE, joules had a robotic eye implanted in his right eye socket.
Despite the tension, Joules and Del elected to stay together. Often times, Mimi tagged a long with them wherever they'd go, since she didn't have any other friends in the new city. Eventually, Mimi asked to be the third in Joules and Del's relationship, as she found she was in love with both of them. Joules had secretly been in love with both Del and Mimi, since he had grown close to Mimi due to their shared trauma. He hesitated since he didnt want to upset del by being too obvious about it, but Del agreed to it, as she was practically always with them, not to mention very attractive.

splatoon 3:
About a year and a half prior to the events of splatoon 3, Cuttlefish had passed down his title of Captain to Joules, and told him of something happening deep within the ancient human city of Alterna, which he asked him to investigate, being the captain now. There were missions and trials down there, but he found that he was too busy investigating the area to go on missions, and he'd need to recruit a new agent. Just as luck would have it, a few weeks later, an octoling would fall into the cavern, who cuttlefish had already recruited to be the new agent 3. The octoling called themself "2714," but Joules decided that they should have an actual name instead of simply an ID number. he nicknamed the octoling Tulip, which eventually became their official name. He saw himself in Tulip, as they too had a super macho attitude and a reckless demeanor, so he took it upon himself to steer them in the right direction, lest they meet the same fate. He and Tulip bonded, and eventually he adopted them as a younger sister, since they apparently had no family beforehand. After the events of alterna, he found out that Tulip had been banned from turf war, and begged the Judds to let them play again, so that they may play on a team with himself, Del, and Mimi. The judds lifted their ban, and the 3 of them formed a team