Arkillo lived in Sector 674, the same sector as Green-Lantern Kilowog, which may be the reason they look somewhat similar. He was also a powerful warrior on his planet and feared throughout the sector. A Qwardian ring came to him and recruited him into the Sinestro Corps. As one of Sinestro's first members, he became the drill sergeant for the Sinestro Corps, training the new recruits. He also oversees the Qwardian Weaponers crafting more rings for the Corps. He kills those who don't work fast enough to make examples of them.
Sinestro Corps WarEdit
Arkillo was present by Sinestro's side when the founder and leader of the Corps gave his speech to his soldiers when Ion aka Kyle Rayner stumbled upon them. He was there when Sinestro ripped the Ion entity from Kyle and broke him down to let Parallax take him over. When the war between the two Corps began, Arkillo was the commanding officer, who led a large group of Sinestro Corps members in the battle between Mogo and Ranx, the Sentinent city. During the battle, he confronted his Green Lantern counterpart and rival, Kilowog. Their battle was not concluded however with Kilowog going off to help his comrades. Arkillo next took part in the attack on Earth. When the GLC arrived, Arkillo went straight back to fighting his GL counterpart, Kilowog. He then preached that Kilowog would lose due to the fear of killing his opponents. Their battle raged across the San Diego area before finally Kilowog defeated Arkillo by dropping an aircraft carrier on him, trapping him. Adding to his humiliation, Kilowog then cut off the unconscious Arkillo's ring finger and took his ring.
Dissension in The RanksEdit
Arkillo survived his fight with Kilowog, and somehow attained a new power ring. He then journeyed to the planet Daxam after receiving a signal for all Sinestro Corps members to converge there that was sent by Mongul. On Daxam, Mongul declared that he was the new leader of the Sinestro Corps. Arkillo protested this and challenged Mongul to a brawl to the death over who should lead the Sinestro Corps. During the fight, Arkillo managed to land a few good hits on Mongul, including impaling him. Mongul though, proved to be too great and came out on top, tearing out Arkillo's tongue, leaving him mute, never to speak out against him again, he later found his tongue and tied it to his neck with a piece of rope. Later, Arkillo was with a patrol of Sinestro Corps members on Daxam where it was revealed that he was enraged over his defeat to Mongul to the point where he would kill anyone who mentioned Mongul's name. He managed to avoid an attack by Ion, taking cover in the shrubs nearby.
The Blackest NightEdit
Arkillo continued to grudgingly serve under Mongul's rule when the corps fled from Daxam, who's residents had regained their powers. The Sinestro Corps fled to Korugar, Sinestro's homeworld and immediately took over. Sinestro arrived and dispatched Mongul, reclaiming his place as rightful leader, which Arkillo was overjoyed by. Faced with the threat of the Black Lantern Corps, Arkillo and his fellow corpsmen decided to unite with the other members of the emotional spectrum against the Black Lanterns. Arkillo went to Earth where a great battle between life and death was taking place. He later remained on Korugar after the end of The Blackest Night where he held the truce with the Green Lantern Corps as per Sinestro's orders. During this time, an incident occurred at the train tracks where Kyle Rayner attempted to stop the accident from occurring though the Sinestro Corps members which included Arkillo and two others did not aid him. When he confronted them, one of the Sinestro Corpsmen attempted to provoke a fight with Rayner which led to Arkillo and his comrade departing in order to not get involved as Sinestro would punish anyone that disobeyed him.
The New GuardiansEdit
Arkillo pursued a Yellow Power Ring that left its Sinestro Corps member and flew off on its' own, eventually reaching Kyle Rayner of Earth. Calling Rayner a "ring thief", Arikillo tried to kill Kyle Rayner, as did many other members of each Corps that came to find out who had "stolen" a ring from each of their Corps. Arkillo was using his Power Ring to verbally communicate with others at this time. Rayner then fled with Saint Walker of the Blue Lanterns to Oa. Arkillo pursued with Fatality, Munk, and Bleez where they broke into Rayners meeting with the Guardians. This led to a fight between the lanterns and the Guardians, which was ended by the apprearence of Larfleeze. The Lanterns escaped to Okaara where Saint Walker of the Blue Lantern Corps healed Arkillo, regenerating his missing tongue
Arkillo and the Lanterns were informed by Sayd, that the one behind the theft of the rings was aboard a ship the size of a solar system called The Orrery. When the lanterns entered they were attacked by Invictus, the creator of The Orrery. They were only sparred on the condition that they kill Larfleeze.
Upon leaving the Orrery, Arkillo found out the Sinestro Corps network had gone off-line. When he arrived back on Korugar, he rescued The Weaponer from execution. The Weaponer then informed him that the Sinestro Corps had been dismantled by Sinestro himself. Soon after Arkillo's ring ran out of power. The Weaponer then provided him with a new ring and power battery, making Arkillo the sole member of the Sinestro Corps with a functioning power ring.
After fighting his way off Korugar, with the Weaponer in tow, Arkillo responded to an alert sent by Kyle Rayner to rendezvous on Odym to assist in preventing an invasion by The Reach. After this, the New Guardians set out for Okaara to confront Larfleeze. After a confrontation with the orange lantern, Invictus arrived and the lanterns all joined against him. During the fight, it was revealed that Sayd was the original ring-thief, and after Invictus was defeated, Arkillo and the rest of the New Guardians disbanded.