Board Thread:Theories and Speculation/@comment-35057921-20200304230629/@comment-43776375-20200305093754

Well the sound four were compatible for the merging, I mean they were compatible with Orocimaru's sage chakra (the curse mark), Kabuto implanted Orocimaru in himself so I guess he could implant even some parts of the sound four

Implanting other people maybe would've required to test the curse mark on them, but I guess Kabuto could adapt himself to them if he would, like he did with Orocimaru