HistoryRyoko's origin matches that of her Earth-616 counterpart.
During the Infinity saga, when the Mad Titan Thanos threatened Earth, Ryoko fought side by side with members of the Japanese super team Big Hero 6 in order to defend Japan from the threat of the alien Builders. After the threat was over, she was invited to be part of the team, which she happily accepted, being part of the group until today.
Radiance has the mutant power to manipulate all wavelengths of the electromagnetic light spectrum as she wishes. Among other things, she can transform herself into a being entirely composed of particles of light that absorb, store and process light, and no physical damage can harm her in this form. Transforming into light allows her to restore damage to her physical form, and sustain herself purely on light, no longer needing food, sleep or air. She uses energy to fly and create bursts of coherent light that can be used as highly destructive rays or concussive bursts capable of incapacitating opponents without killing them. She can fly at the speed of light, which allows her to take seven turns around the Earth in one second. Her energy capacity is practically unlimited. She is able to manipulate external light to create illusions and constructions of solid light (in a very similar way to the hero Quasar), holographic images of light, folding the particles of light around her to render her invisible, projecting holograms around her that allow her to assume any appearance, and she can use her light to hypnotize opponents and give them non-suicidal commands; and the greater the ambient light present the greater her powers.
In addition to her super powers, Radiance is also one of the most experienced programmers in her reality. She found a great deal of time to work on computers.