Excalibur

Excalibur or Caliburn, from the Welsh Cadedfwich "hard cleft" or "strong breacher" is the legendary sword of King Arthur of Camelot.

History
The sword's legend takes many forms, with many separate origins, uses, and powers. Some legends connect it to the sword that Arthur pulled from the stone

Passive
God-Killer: This weapon ignores all immunities and resistances to physical and a single type of damage (Radiant)

Resistance: This item gives you resistance to a single damage type (Radiant).

Rending: Should the artifact or weapon not have the 'Power Immune' passive ability, this artifact can cut through it, ignoring resistances and immunities and decreases AC by 1 for every attack. If targeting a weapon, the user must succeed on a DC 15 save to not have their weapon broken.

Power Immune: The artifact is immune to all effects and powers not cast by the wielder. This doesn't extend immunity to the wielder. It cannot be broken, transported (seperately from the wielder), or altered by an opponent.

Active
As an action, the user may summon Holy Aura for 10 turns. They may only do this once until completing a long rest.