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
In film
Skynet and Terminators – Terminator
In video games
Grimoire Weiss – Nier
Aigis – Persona 3
Master Sword – The Legend of Zelda: Skyward Sword/Breath of the Wild. 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