Brother Rrkak was a male Force-sensitive being who, during the High Republic Era, was part of the Nihil's group known as the Children of the Storm. He served under the leadership of their Father, who was an Ithorian scientist and Baron named Boolan. A group consisting of Jedi, the ex-Nihil Tempest Runner Lourna Dee, and the Sephi Tey Sirrek launched an operation to rescue a Yacombe girl from Boolan's base, Shingcu Station. Rrkak, along with Sister H'Tar, was sent to confront the invading party. Rrkak fought against Trandoshan Jedi Master Sskeer, successfully using mist-bonds to overcome him. He died when the station exploded, causing debris to fall on him.