The theorem states that, for a field $k$ of characteristic 0, any $k$-linear tensor category with $End(1)=k$ satisfying a condition that each object is annihilated by a Schur functor, is equivalent to a category of parity preserving representations of a supergroup $G$.
The statement is independent of the fiber functor, yet the proof seems to construct one by itself, by constructing a functor to $R$-modules for some large $R$ first and modifying it. I would like to understand how the proof proceeds from here.
Is this supposed to be analogous to the proof of Deligne for the non-super case? I found that the approach in Joyal & Street which realize $G$ as a spectrum of coend of the fiber functor is particularly clear to grasp. Is there a similar way of obtaining a supergroup out of a super fiber functor ?
One last question is: what aspects of super vector spaces make it possible to capture every tannakian categories?