Yōji Aburame

Yōji was raised by an abusive father who was jealous of Yōji's natural talent. When Yōji accidentally spilled juice on his father on his fifth birthday, his father slit his throat to punish him. Yōji retaliated by killing his father. Orphaned, Yōji was soon recruited into Root, a faction of the Anbu led by Danzō Shimura. Because he'd lost the ability to speak when his father attacked him, Danzō taught him how to use the insects that inhabited his body to produce words. Though effective, it made his voice sound weird and tired him out, for which reason he preferred to remain silent. When Itachi Uchiha joined the Academy, Yōji was assigned to pose as a student and observe Itachi, passing along reports about Itachi to Danzō. A year after Itachi graduated from the Academy, Yōji was assigned to Itachi's Team 2 so that he could continue to watch him. The two never spoke, and Itachi left the team after only a few months. A few years later, when Itachi joined the Anbu's Team Ro, Yōji - using the codename Sugaru - was also added to the team. Officially he was just another member, but Danzō informed Itachi that Sugaru's sole responsibility was to keep Itachi safe from harm. As the Uchiha clan began moving towards a coup, Sugaru continued to watch Itachi both during and after Team Ro's missions, the latter in secret. In doing so he learned of Itachi and Shisui Uchiha's plans to try and stop the coup by using Kotoamatsukami on Fugaku Uchiha. After reporting this to Danzō, Sugaru used his insects' poison to subdue Shisui, enabling Danzō to take Shisui's Mangekyō Sharingan for himself. Shisui escaped before his second Mangekyō could be taken, but the insects' poison couldn't be removed and he would die anyway; the poison would then break down so it wouldn't show up during an autopsy. Sugaru continued to watch Itachi on Danzō's instructions. When Itachi left the village following the Uchiha Clan Downfall, he called out Sugaru, aware that he would be followed wherever he went. Sugaru didn't believe Itachi could do anything to stop him, but was quickly proven wrong: Itachi used Tsukuyomi on the insects inhabiting Sugaru's body, preventing him from moving. He then used Amaterasu on Sugaru, burning him and each of his insects until only ashes remained. Sugaru, via his insects, cried out in agony as he died, finally avenging Shisui.