1- It's KCM...
2- Since he has Kurama's chakra in him, his markings are similar as Naruto...
Because he used the same sealing formula,,,,,,,,,,,,,,why does minato have the same marking on him just like Naruto when he is in bm ? :erm:
Very possible since used the same seal on Naruto plus i think it's also due to Kurama's Yin chakraBecause he used the same sealing formula,,,,,,,,,,,,,,