The Blessings of Maa Baglamukhi make a divine protecting defend in the shape of the aura all-around a person thereby guarding him/her from malefic energies in the form of black magic spells or evil eye. Another etymology suggests that valga means "to paralyze" and symbolizes the strength of stambhana, "paralysis" https://www.youtube.com/shorts/5VeSyP9JRw0