The Latin word for "king" is rex. It's 3rd Declension, masculine. The genitive form of rex is regis.
The 3rd person, present tense, form of the verb "to be" in Latin is est.
Neither rex nor est appear in "Balenciaga." Someone is pulling our leg and creating an urban legend.
“Neither rex nor est appear in “Balenciaga.” Someone is pulling our leg and creating an urban legend.”
True, but they did add an extra A to that roll of tape to make it BAALenciaga.