  The classification of emergent spinor fields according to modified bilinear
covariants is scrutinized, in spacetimes with nontrivial topology, which induce
inequivalent spin structures. Extended Clifford algebras, constructed by
equipping the underlying spacetime with an extended bilinear form with
additional terms coming from the nontrivial topology, naturally yield emergent
extended algebraic spinor fields and their subsequent extended bilinear
covariants, which are contrasted to the classical spinor classification. An
unexpected duality between the standard and the exotic spinor field classes is
therefore established, showing that a complementary fusion process among the
spinor field classes sets in, when extended Clifford bundles are addressed in
multiply-connected spacetimes.
