The Holy Excalibur is sentient, not able to talk, but to know who is worthy of it. Will burn the non-worthy into flames if they attempt to wield it. Can release a beam of light that can purify anything. Often called the Sword of Gods. Obviously, not a normal excalibur. Is glowing with blinding holiness. Will stay with the chosen holder until either they die or the Holy Excalibur finds a new worthy person. Can automatically parry projectiles and melee attacks. And this is set in the medieval age.