Sasuke Tanaka is the reason why Hideo Tanaka made the Neuro Link and the algorithm.
Sasuke Tanaka was really ill, and in desperation his parents sent him in into a study conducted by neuroscientist Dr. Dana Taylor. The study was made to test out a biological advancement in medicine. Or that was what the parents thought. Dr. Taylor actually used it as a cover up to find extremely intelligent children who can take part in her actual study of brain-to-AI technology. Midway through the experiments, Mina Tanaka (mother) withdrew her son out of the study and requested that her son just stay home. However Dana Taylor did not like this.
One day, when Sasuke and his brother Hideo were playing in a park, one of their toy eggs was thrown too far into the trees. Hideo sent Sasuke to retrieve it, but Sasuke never came back.
Sasuke was held against his will by Dr. Taylor and subjected to daily experiments. Through his time there, he met Jax, Dr. Taylor's adopted daughter, and established a strong, affectionate friendship with her. One day, Sasuke gave up his scarf, the only attachment he had left to his family, for a day of freedom and attempted to escape with Jax's help, but failed. He had an opportunity to escape, but could not bear to abandon Jax and pledged himself to the study. Over time, Sasuke lost more and more of his humanity as his mind was downloaded into data, eventually becoming emotionally detached from the people that he had once loved, such as Hideo and his family. By the time his body had succumbed to the disease, his mind had been fully downloaded.
Appearing a few months before the Warcross Championships, he started hacking the game and infiltrating Henka Games with the help of Kenn. He couldn't be found as he left no trace, and he used the alias "Zero", due to his being Project Zero in Taylor's experiments.
. Renoir Thomas also warns him that Emika is on Zero's trail. Seeing that Emika wouldn't, he blows up the Phoenix Riders' building, causing Hideo to remove Emika from the games for her safety.
Zero warns her that because her name is first on the assassination lottery in the Dark World, she is being targeted by assassins.