Yea, that boy is being controlled by the one in the cloak. In the spoilers the cloak one said that he could never forgive Sasuke. For killing Itachi? perhaps..and now he's using that blonde boy to test Sasuke, to see how strong he is before engaging him in a fight.
Since the manga seems to be focused on sasuke and salad the cloaked man should reveal himself, and get defeated in the mini series. Orrrrr it could be a 'to be continued' towards the Bolt movie with Bolt using his signature new move to defeat sir cloak alot :sdo:
I don't believe he's shisui or any other uchiha cause they ded except for Sasuke. That last akatsuki member. I'm gonna lose my shit when the hood is pulled back and it turns out that it's Madara. Jesus, we haven't even seen Madara 'die' or get buried, or anything at all but I'm not counting on it just yet. You're getting to me minamoto, you are getting to me...