Rikiya is a huge, tall and very muscular man.
He wears a black tank-top with jeans and sneakers, as well as a plague mask that covers his head. He also wears massive gauntlets and knuckledusters on his fists too.
Rikiya seems to require energy to move effectively, as when he charged through the gate at the beginning of the raid, he complained about how it was too early for stuff to happen. After he was temporarily captured and absorbed the energy of people around him, he declared he 'felt like a new man'.
In general, it seems Rikiya enjoys absorbing energy from others, which may simply be a byproduct of his Quirk or indicate that Rikiya is normally rather lazy. He also demonstrates a slightly perverted side during his battle against Nejire Hado where he suggestively moved his hands at the idea of touching her after his Trigger worn out.
He escaped, using a Trigger on his Quirk, and absorbed the vitality from the police and heroes to become stronger and break the bindings and continue fighting. Himiko Toga in the form of Deku tricks the heroes into sending Rikiya crashing down to the underground tunnel where his boss is fighting. He fuses together with Overhaul, becoming a monstrous amalgam of flesh to fight Deku. After an intense battle, Eri uses her Quirk to defuse him from Overhaul and he is arrested along with the rest of the Hassaikai.
Overall Abilities: Being an Eight Bullets member of the Shie Hassaikai, Rikiya is a very formidable individual. While he commonly overwhelms his opponents with his enormous size and brute strength, Rikiya also uses his Quirk, Vitality Stealing, to absorb the stamina of his adversaries, simultaneously strengthening himself, while weakening his opponents. Rikiya's overall capabilities make him a rather dangerous combatant who can singlehandedly contend with foes that outnumber him.
During the Shie Hassaikai Raid, Rikiya was the first line of defense to take on the raiding team of police officers and Pro Heroes. After incapacitating 2 police officers, he faced off against Ryukyu, at the time No. 9 hero, Nejire Hado of U.A.'s Big 3, Tsuyu Asui, and Ochaco Uraraka, who managed to eventually subdue the Eight Bullets member. While detained, however, Rikiya's Quirk automatically activated, revealing that, prior to his battle against the Ryukyu Squad, Rikiya had taken a dose of the Quirk-enhancing drug, Trigger. Under the effects of Trigger, Rikiya can absorb the vitality of nearby people through inhalation alone, without having to make physical contact with them. With this boost in power, Rikiya regained consciousness, reinvigorated, broke free from his restraints, and was able to fight against the Ryukyu Squad better than he did compared to the beginning of the bout, for 20 minutes, especially since Nejire, Tsuyu, and Ochaco were stamina-drained due to the Rikiya's Quirk. It was only when the effects of the Trigger drug wore off that Rikiya was defeated by the weakened Ryukyu Squad's final, combined assault.
- Enhanced Strength: Even without activating his Quirk, Rikiya exhibits superhuman brawn, befitting his massive build. On two separate occasions, he effortlessly smashed through a wall and a locked gate, knocking 2 policemen into the air while doing so, and casually damaged the jamb while readying his next punch.
- Enhanced Durability: Rikiya has shown to be fairly durable, as he was still conscious after being temporarily subdued by the Ryukyu Squad, much to the shock of Ryukyu herself, as she believed she had rendered Rikiya unconscious. After being resuscitated due to the Trigger drug, Rikiya was able to shrug off energy blasts from Nejire, although Nejire had some of her stamina drained by Rikiya at the moment, resulting in the heroine producing weaker blasts.
Vitality Stealing: Rikiya's Quirk allows him to siphon away other people's stamina by inhaling their strength away from them. He can use the stolen stamina to greatly increase his own size and strength. In order to use his Quirk, Rikiya needs to be touching the target.
Metal Gloves: Rikiya wears a pair of metal gloves on his hands to augment his punches.
Trigger: Rikiya uses this drug to enhance his Quirk so he can siphon people's stamina without needing to touch the victims.
They have not been seen interacting with each other, but it can be assumed that Rikiya is just as loyal to Overhaul as much as the rest of the Eight Bullets.