Beast Spirit of Darkness
The Beast Spirit of Darkness (闇のビーストスピリット Yami no Biisuto Supiritto) was created from Ancient Sphinxmon. It was found at some point by Cherubimon, who corrupted it into the Corrupted Beast Spirit of Darkness and forced on Kimura Kouichi, who then became Velgmon. It purified again after being scanned by Minamoto Kouji when Kouichi accepted that it and he were nor inherently evil. It then allowed him to spirit evolve into Kaiser Leomon.
(Note: Is called Spirit of Darkness K in TCG.)