Board Thread:Episode Discussions/@comment-1181222-20180328101515/@comment-34769354-20180328120836

Vladosaurus wrote: @Thekillman He doesn't have a curse mark, and that was the standard way of implementing Jugo's clan sage abilities into other humans.I'm not over ruling the possibility at all especially since Mitsuki does have a demonic apperence in SM, but you still need to be tough to sustain sage mode.

But he got the ability of the Clan Juugo (that gives him the form "demonic" when enters in Sage Mode, plus this ability gave him the ability to asborb passively the energy nature like Kabuto did on his).