Subspace has killed Medkit and grabbed his skin and perfect condition to live longer because his rot got almost 95% of Subspace, so now Subspace replace medkit, He Hides the fact that Medkit was dead long time ago.Before he changed skin tell to the superiors about his plan, to inflitrate lost temple and the fact blackrock knows about the truth and Meds death. The doctors helped Subspace to be in Med's body.Subspace knows Medkit personality, so he acts like him. Also imitating his voice.