Sword of Power (Netflix)

The Sword of Power (also called the Sword of Grayskull) in Netflix's He-Man and the Masters of the Universe is the totem and weapon of the deemed "Champion" of Castle Grayskull, through which the protector of Grayskull would wield its Power in their sworn duty to protect Eternia.

History
The Sword was crafted by King Grayskull over a thousand years ago, wielded to defeat King Hiss and the Snake Men. After Grayskull's death, the Sword was kept in Castle Grayskull, under the watchful eye of its guardian, the sorceress Eldress. For over a thousand years, none ever wielded the Power of Grasyskull by imperial decree, as the royal family believed the Power was too great for anyone, even the king, to wield.

That came to an end when the power-hungry Prince Keldor managed to find and enter Castle Grayskull, bringing along his abducted nephew, Prince Adam (apparently to access the Castle) and then demanded the Eldress bestow upon him (Keldor) the Power of Grayskull.

Eldress agreed in exchange for the safe release of Adam, and then offered Keldor the use of a totem in order to channel the Power. The Sword of Power was one of the offered totems, while the second was a sceptre. Keldor snubbed the sword, deeming it symbolic of a soldier, one who serves Power, while he was appealed to the scepter, seeing it as a symbol of rule and leadership. Taking the rod and bathing it (along with his left hand and forearm) in the Power, Keldor's evil corrupted it and instead buffeted the royal pain with a perverse and malevolent version of it, Havoc, striping away the flesh of Keldor's limb which resulted in his being accursed with Havoc.

Keldor demanded Eldress restore him, though she claimed she could not, that Keldor had brought this upon himself. When his uncle moved to attack the Eldress, young Adam, having grabbed the Sword, raised it in her defense, his actions and bravery deemed the young prince worthy of being the Champion.

Alas, to protect Adam and the Castle from Keldor, Eldress used her power to send them all away (while apparently dying from her own wounds). The Sword was found by Adam's father and Keldor's brother, King Randor, wherein he ordered it taken to the vaults of Eternos to ensure no one would ever find or access Castle Grayskull again.

Ten years later, the Hand Witch, Teela, at the direction of her employer, Evelyn, broke into Eternos and stole the Sword, through which the Eldress spoke to Teela, instructing her to deliver it to the Champion.

Eventually, Teela succeeded in delivering the Sword to the Champion, an amnesiac Adam, now living with the Tiger Tribe. Confronted by Evelyn and her wicked cohort, Kronis, Adam tapped into the Power for the first time, transforming him into the Champion, later called He-Man, by his friends.

Though Evelyn and Kronis were driven off, they continued to search for the power when they encountered Keldor, whom all assumed to be thought long dead. They conspired together to take the Sword from Adam and succeeded when Keldor managed to get close to his nephew and grab the weapon while instructing Kronis to blow up Adam and his friends, burying them under a rockslide.

Taking the Sword, Keldor, Evelyn and Kronis managed to access Castle Grayskull again, and were shortly after followed by Adam, Teela, Krass, Duncan and Cringer. Taking the others as hostage, Keldor demanded Adam unlock the Power in order to mend his malady, lest he would kill his friends. Adam stalled long enough so Teela could undo their restraints, with that business done they all tried to escape, only for their assailants to block their path. Due to infighting between Keldor and his old accomplices, Adam got an idea... and used the Sword to share the Power of Grayskull with his friends, empowering them as he had been, giving them new equipment, weapons and abilities.

Together, they drove out the villains and continued to protect Castle Grayskull and use the power for good.