MKI or mecha sonic was the result of Grimers and Dr. Robotnik's' project mettalix. MKI's first assignment was to capture Amy Rose to lure sonic into a trap on the miracle planet, it worked, but sonic came off best saving Amy and destroying MKI. With the destruction of his creation Robotnik made a Mettalix factory in the special zone, he ran a large production until the mettalixs' ignored their programming and became self aware, they wanted to rule Mobius for themselves. Because together they were so powerful Robotnik had to join forces with sonic and the gang to beat them.