The blessings of Maa Baglamukhi create a divine protective defend in the form of the aura around somebody therefore guarding him/her from malefic energies in the form of black magic spells or evil eye. Yet another etymology implies that valga indicates "to paralyze" and symbolizes the power of stambhana, "paralysis" https://www.youtube.com/shorts/5VeSyP9JRw0