Sentient weapon

A sentient weapon is a common plot device in many works of fantasy, mythology, and science fiction, and is related to the classic motif of the magic sword. Sentient weapons may be human, robotic, or magical (as is the case with any non-technological weapons, such as a sword), but not all magic weapons are sentient. A sentient weapon may experience a moral conflict from its specific nature as a weapon, or may function as the villain, which, through its intelligence, is able to gain power. Another possibility is that it assists the wielder, or is merely neutral.

In fantasy and mythology

 * Kullervo's Sword from the Kalevala
 * Anglachel – The Silmarillion
 * Stormbringer – The Elric Saga
 * Nightblood – Warbreaker (a.k.a. Sword Nimi – The Stormlight Archive)
 * Kazid'hea – The Legend of Drizzt
 * Need – The Oathbound and subsequent novels
 * Sword of Summer – Magnus Chase and the Gods of Asgard

In film

 * Skynet and Terminators – Terminator

In video games

 * Grimoire Weiss – Nier
 * Aigis – Persona 3
 * Master Sword – The Legend of Zelda
 * Eyelander – Team Fortress 2
 * Transistor – Transistor
 * Soul Edge and Soul Calibur – Soulcalibur series
 * Umbra – Elder Scrolls series
 * Lilarcor – Baldur's Gate II
 * The weapons in Boyfriend Dungeon
 * Modwyr – Pillars of Eternity II: Deadfire
 * Caliburn – Sonic and the Black Knight
 * Blades - Xenoblade

In anime and manga

 * Senketsu – Kill la Kill
 * Several characters in the Soul Eater series
 * Derflinger – The Familiar of Zero
 * Several characters in the Wakfu series
 * Ashgan – The Witch and the Beast