Why does

[Whatdidyoucallme1]

Minato have those circle things around him on page 15 naruto 641

 

[hixa kuogame]

because he swapped places with obito
thats how the jutsu combo worked

 

[Lamb]

Minato and Tobirama switched places. Tobirama brought Obito along with him. Those spheres are Obito's which are left behind after the swap.

 

[iNotorious]

Switched places