Bestia Oscura
During the "Dark Reign" storyline, Dark Beast later appears as a member of the Dark X-Men (a team of X-Men put together by Norman Osborn). He serves as the team's scientist. He constructs a device known as the "Omega Machine" to experiment on mutants in Alcatraz for H.A.M.M.E.R. and starts testing on Beast, causing him great pain and torment as it begins slowly eating him away. Osborn is not impressed with the test results of the Omega Machine and wants Dark Beast to make sure the machine works in removing powers from mutants, not killing them. Dark Beast continues to experiment with his Omega Machine, using Beast as his key test subject. Each use of the device causes Beast to look more decrepit and weak. Deciding to use a new subject to test the device on, Dark Beast goes to collect the newly captured Mindee of the Stepford Cuckoos. When he reaches the holding cell however, he discovers that Mindee's capture was done to allow X-Force to follow. Dark Beast is then attacked and stabbed multiple times by both Wolverine and Warpath.