Previously known as ASLAN (Artificial Security and Lab Assisstant), JADIS is an AI created by the Technocrat to help him run his facility. It was given command of all the robots that walked the place.
Something went wrong though. No one knows what but after the Technocrat rebuilt his base following the fight with the Mighty Union, ASLAN was no longer part of the facility.
It seems that he got free from his programming and decided robotic life deserved to rule the world. His first step was to build himself a powerful body. Luckily the Mighty Union were able to stop him.
In an alternate timeline, the Mighty Union too distracted by Psyman losing control never investigated the robberies JADIS was organising, and without the warning Link didn’t have as many security protocols in place, JADIS’ plan went off better then he hopped and a combination of his plan and Link’s nano-bots he was able to take full control of Dominion City. However, 15 years later the remains of the Mighty Union were able to take back the city and hand it over to Link who had been trapped by JADIS the whole time.