Excalibur

This legendary weapon is said to grant powerful magic to its wielder and that only the rightful ruler of the land is suitable to carry it into battle. While you are attuned to it, Excalibur grants you the following benefits:

• If you are the rightful wielder of Excalibur, it instantly attunes to you and does not take up an attunement slot.
• You gain a +4 bonus to attack and damage rolls made with this weapon. 
• When you attack an object with this magic sword and hit, maximize your weapon damage dice against the target.
• When you attack a creature with this weapon and roll a 20 on the attack roll , that target takes an extra 4d6 slashing damage. Then roll another d20. If you roll a 20, you lop off one of the target’s limbs, with the effect of such loss determined by the Narrator. If the creature has no limb to sever, you lop off a portion of its body instead.
• You can speak the sword’s command word to cause the blade to shed bright light in a 10-foot radius and dim light for an additional 10 feet. Speaking the command word again or sheathing the sword puts out the light.
• When you are reduced to 0 hit points but not killed outright, you can drop to 1 hit point instead. You can’t use this property again until you finish a long rest. 
• You have advantage on Insight and Persuasion checks made against anyone but creatures you consider to be your close allies and companions.