The Kenny Koopa Series is a spin-off of the Mario series, starring Kenny Koopa and many other Koopa characters as well as Bowser from the Mario series. It was created by Underworld Games. and its first game was released for the Nintendo DS.
King Bowser led a Koopa Troop, Kenny Koopa was their leader, but once he realized that the path he was taking was wrong, he betrayed them. As a result, Bowser left him scarred for his betrayal. But luckily, Kenny managed to escape the horrible scene. And now that he has found new friends. He intends to seek revenge on Bowser for scarring him. So the adventure begins.
Long before the events of Kenny Koopa's Revenge, Bowser was working on a powerful being that was in fact a dark clone of Kenny Koopa named Yinnek Koopa. Since he was a very good soldier before he left. Bowser thought that having two Kenny's would be a very powerful addition to his militia. King Bowser eventually felt that Yinnek Koopa was becoming too strong and rejected the experiment. The dark being was then taken to the underground of underground of Bowser's Castle for storage.