User blog comment:B214/Question and Answers 6/@comment-37165251-20190121223120

in the Light Novels it is said that :

"The Scabbard of Excalibur (スカッバードのエクスカリバー, Sukabbādo no Ekusukaribā), the sheath of the original Excalibur. It can emit an holy aura the grants the wielder limited invulnerability."

Is there anywhere said something more specific what is meant with "limited invulnerability" ? Is it a shield, or a healing ability or both combined that is dependent on Stamina or magical power of the Wielder ?