King Arthur: Excalibur Rising (2017)

In 520 A.D., King Arth-yr falls in battle to his son Mordred, instructing Sir Bedivere to return Excalibur to the Lady of the Lake before his death. Nearly two decades later, Bedivere, imprisoned alongside Owain, Arthur's son, implores Owain to find Merlin before passing away. Owain, believed dead but saved by the Lady of the Lake, acquires Excalibur. Yet, Mordred and his mother Morganna, in possession of the Holy Grail, relentlessly pursue the sword, using dark magic to rejuvenate Morganna.