Gazimon DX(Dark Exterminator) is the reincarnation of an ancient demon who terrorized an alternate dimension. After many deaths of both comrades, enemies,and innocent bystanders he was defeated. As his punishment he was stripped of his physical form and sentenced into the Digital World.
Upon entering this new realm he immediately felt an unwavering pain overcome his body. He realized that without a body he would soon die. He then noticed a small creature and bonded with it against its will. In order for both of them to survive he sealed all of his powers away within a locket. As a result all of his previous memories were lost.
Each time he gains a new form more of his memories return until finally his dark soul completely takes over the body and transforms him into his previous incarnation.