The improved deformation behavior of bulk metallic glass composites (BMGCs) compared to monolithic glasses render these materials interesting for possible applications. However, the details of the deformation mechanisms are still not fully clear. Here, we report on BMGCs containing metastable β-Ti dendrites, crystals with dislocation-mediated plasticity or shape memory crystals, revealing that the overall deformation behavior can be significantly altered by the deformation characteristics of the crystals and/or by cooperative shear events of shear bands in the glassy matrix and strain-induced ω-Ti bands in β-Ti dendrites. If the crystals deform via dislocations, SBs are narrow and getting mature. In comparison, SBs in shape memory BMGCs continuously broaden by following thick martensitic plates without maturing, and broad SBs bifurcate, inducing formation of more martensitic variants and promoting strain delocalization. The broadening and bifurcation cause SB blunting, accounting for the superior plasticity and work-hardening capability of shape memory MGCs.