DJ Octavio's History
DJ Octavio (DJタコワサ将軍 DJ Takowasa shōgun?, lit. General DJ Takowasa) is the leader of the Octarians and the central antagonist of the Splatoon Trilogy. He serves the main antagonist of both Splatoon and Splatoon 2, a mentioned antagonist of Octo Expansion and a minor antagonist turned anti-hero of Splatoon 3. He is Craig Cuttlefish's former friend turned Archnemesis.
Before Splatoon
DJ Octavio has been the leader of the Octarians for an extremely long time, as far back as when they and the Inklings were allies. However, rapidly rising sea levels forced the two species to fight over land, and Octavio held his position as the leader of the Octarian army during the resulting Great Turf War. This even led him to battle his previous ally Cap'n Cuttlefish "during the bitter siege of Arowana Castle", which the Octarians lost.
Despite some early victories for the Octarians, a combination of good luck, superior tactics, and a higher number of limbs resulted in the Inklings being victorious, forcing Octavio and the rest of the Octarians underground into domes later called Octo Canyon and Octo Valley.
Splatoon
Around 100 years later, during the events of Splatoon, dwindling energy reserves underground led the Octarians, still led by Octavio, to steal the Great Zapfish and a series of regular Zapfish that the Inklings used for power. To counteract this before the problem got too severe, Cap'n Cuttlefish secretly recruited a young Inkling that he nicknamed Agent 3 to join his New Squidbeak Splatoon, intending to recover the Zapfish and defeat the Octarians again.
However, after Agent 3 defeated the Octowhirl, Octavio kidnapped Cuttlefish himself, forcing Cuttlefish's granddaughters, Agents 1 and 2, to guide Agent 3 to Octavio's base. Finally, in Enter the Octobot King!, the group was reunited as Octavio battled the New Squidbeak Splatoon. During the battle, the two agents revealed their true identities as the Squid Sisters and overrode Octavio's music, freeing Cuttlefish and spurring Agent 3 to finally defeat him, rescuing the Great Zapfish and saving Inkopolis in doing so.
After this fight, Octavio is kept imprisoned in a snow globe next to Cuttlefish in Octo Valley. If the final boss battle is repeated, it is explained that Octavio broke out while Cuttlefish was distracted by eating crabby cakes.
Splatoon 2Around nine months after the Callie vs. Marie Splatfest, Cuttlefish deserted his shack in Octo Valley, giving Octavio the chance to escape. Marie was the first person to notice, after Callie's disappearance, and shortly afterwards, Octavio stole the Great Zapfish a second time and fled to Octo Canyon. Realizing the two events had to be connected, Marie stationed herself there and recruited a new young Inkling as Agent 4, and the two worked together to rescue Callie and the Great Zapfish.
Eventually, in "Tide Goes Out", Octavio was discovered to have kidnapped and brainwashed Callie into working for him. In the ensuing battle, Agent 4 defended their attacks for long enough so Marie could shoot off Callie's hypnoshades, returning her to her normal self. With some help from Sheldon, the group eventually defeated Octavio a second time, imprisoning him in a new snow globe in Octo Canyon. If the battle is repeated, it is explained that Octavio was able to escape thanks to Callie wanting to try on the hypnoshades again.
Splatoon 3
In Splatoon 3, DJ Octavio appears in the single-player mode, Return of the Mammalians. Unlike previous appearances, he's the first boss of the game, piloting a modified version of the Octobot King called Octobot King L3.Gs.
Shortly after Agent 3 clears out the Fuzzy Ooze blocking the center of The Crater outside Splatsville, DJ Octavio arrives and accuses Craig Cuttlefish of being behind the disappearance of his entire Octarian army. In turn, Cuttlefish accuses Octavio of stealing the Great Zapfish from Splatsville, provoking a fight between Agent 3 and the Octarian leader.
After being defeated, DJ Octavio laments that Agent 3's gear is too powerful as Cuttlefish comments on how easy the fight seemed. An irritated Octavio asserts that he didn't steal the Great Zapfish this time, explaining why his mech was so much weaker than previous models. Before anyone can ponder this further, a huge mass of Fuzzy Ooze erupts from below, dragging Octavio's mech through the ground with enough force to shatter it. Octavio is seen tumbling into the darkness along with everyone else, his fate left unclear for most of the game.
Although Octavio is not seen in Alterna, he apparently recovered his mech and began upgrading it with technology found around the underground city, allowing it to fly into space. He makes a sudden appearance during the battle against Mr. Grizz, catching Agent 3 and their Little Buddy after they were blown off of Mr. Grizz's rocket. With the CEO of Grizzco Industries supercharged by Fuzzy Ooze, Octavio counters by playing "Calamari Inkantation 3MIX", curiously calling it a heavenly melody, on the Octobot King's speakers; this infuses Agent 3's companion with tremendous amounts of "marine life energy", allowing them to transform into Hugefry.
As Hugefry battles Mr. Grizz head-on, DJ Octavio had Agent 3 take control of the Octobot King in order to use its giant Ink Vac to drain the Fuzzy Ooze from Mr. Grizz's body. When even this proved insufficient to stop Mr. Grizz, Octavio switched the Ink Vac to cannon mode, converting the absorbed Fuzzy Ooze into a massive ink laser that Agent 3 fired right into Mr. Grizz's face. With the Ursine Anomaly defeated for good, Octavio used his mech to transport himself, Agent 3, and the Smallfry back to Earth. He presumably regained his army following the destruction of Fuzzy Ooze, but it is unclear if his team-up with the New New Squidbeak Splatoon was a temporary alliance against a common foe or a sign that he may be moving away from his previous antagonism, although the fact that he called the squid sisters theme a "heavenly melody" after having once hated it makes a better case for the latter
