Oluo is a very self-confident, outspoken individual, and enjoys boasting about his own prowess. Despite his obnoxious demeanor, he is the best out of Levi's Special Operations Squad; his 39 solo kills (highest solo kills out of his peers, bested only by Levi) fuels his haughty nature. Oluo serves as a kind of comic relief, as his cocky nature is rarely taken seriously, and he is also shown to be somewhat clumsy, frequently biting his own tongue on accident.
He also casually attempts to imitate Levi, such as his rough speech and confident attitude, which causes him to be at slight odds with Petra.
Oluo enlisted into the Survey Corps sometime after the fall of Wall Maria. At some point before the Battle of Trost, Oluo was saved from a Titan by Levi.
Oluo was hand-picked by Levi to form a Special Operations Squad alongside Petra, Erd, and Gunther. Their task was to safeguard Eren during missions and, if necessary, to kill him should he lose control of his Titan powers. Oluo gave Eren a hard time, making clear that he would not trust the newcomer easily.
During the Survey Corps' 57th Expedition, Oluo's duty was to protect Eren, and, along with the rest of the squad, was left in the dark of Commander Erwin's true objective, which was to capture the Female Titan. Eventually, Oluo and the rest of the squad came to blows with the Female Titan. Though they fought fiercely, Oluo's teammates were quickly killed, leaving Oluo to fight alone. Enraged by the deaths of his friends, Oluo fought to the very last, but he, too, was eventually overwhelmed and killed.
He was a very skillful warrior who has an impressive Titan kill record of 48 kills: 39 solo kills and 9 team kills. Despite being very competent at slaying Titans alone, Oluo was fine-tuned to work in coordination with the rest of the Special Operations Squad, and together, they could launch coordinated strikes without so much as speaking.
Eren Yeager: Oluo dismissed Eren as a newbie, and did not trust his ability to control his Titan powers. When Eren partially transformed on accident, Oluo was convinced he was up to no good and threatened to kill him on the spot. Later, realizing his rash reaction, Oluo hopes Eren will forgive him, though he says so in his usual rude manner.
Levi: Fiercely loyal to Levi after having had his life saved by him, Oluo has attempted to mold himself into the image of the man he respects. Oluo has attempted to copy Levi's speech patterns, cool attitude, and even smaller details like his fashion sense and his ability to face Titans all alone. After Levi saved his life, Oluo declared that he would follow him anywhere.
Hanji Zoe: For the most part, Oluo considers her looney and crazy. He initially dismissed Hanji's desire to capture and experiment on Titans, seeing it as unreasonable, but eventually came to understand her point of view. Oluo apologized to Hanji, stating his life is worthless compared to the importance of her research, though Hanji demanded he never consider his life worthless.
Petra Ral: Petra is frequently annoyed by Oluo's rudeness and his obnoxious habit of mimicking Levi. Oluo dismisses her remarks, thinking her to be an aspiring, naggy wife. Despite their bickering, the two have a long history of working and fighting alongside each other, leading to a powerful friendship and bond, and Oluo was devastated by her death.
Erd Gin: Oluo trusted Erd both as a teammate and as a friend. However, Erd did not hold back on pushing Oluo's buttons, revealing to Eren some of Oluo's less respectable moments.
Gunther Schultz: Gunther and Oluo worked well as a team, though Gunther would occasionally scold him and the others for their unfocused attitudes.