Board Thread:Theories and Speculation/@comment-28559671-20160703214120/@comment-5407586-20160704183752

Yeah. Since we don't know of any blood relation between the two, it could go either way. But I remember that Obito was thrilled at the idea of taking Shisui's right eye for himself. While Kotoamatsukami is a very powerful genjutsu, I don't really see him sacrificing Kamui for it, which "could" hint at the possibilty of keeping both powers (aka, Eternal Mangekyō), but it's just speculation. We don't even know if compatibilty between donor and receiver is really all it takes to gain the eternal light, since only Indra's transmigrants could do it.