Mystey man

[monsoonfox]

When Orochimaru revived the four hokages he used four zethsu for that. Still two zethsu's were remaining . Among them one is used for Orochimaru's body One more left. My guess is that the one left zethsu is followed Sasuke and party in secretly. Now he is in the position that able to take revenge by sparing the remaining life in Sasuke

 

[Young Vongola]

That zetsu was absorbed by Jugo + Karin would know it was a Zetsu