Mjølnir is a powerful enchanted war-hammer forged by the Dwarves for the Asgardian Royal Family, and was used by Odin before he passed it down to Hela and then Thor. The hammer was used extensively by Thor as his primary weapon until it was destroyed by Hela in 2017.

Five years after the Snap, Thor time traveled to an alternate 2013 and brought its Mjølnir into the main timeline's 2023, where it was used by Steve Rogers dIt was made from this special metal from the heart of a dying star.―Thor to Korg[src]Mjølnir was forged from Uru in Nidavellir per Odin's request by the Dwarves.[1] During Odin's conquests of the Nine Realms, his eldest daughter, Hela, possessed Mjølnir and with it she helped her father in his battles. Only after Odin imprisoned her in Hel was Mjølnir taken from her.[4uring the Battle of Earth to fight Thanos. Afterwards, Rogers time-traveled to the alternate 2013 and returned Mjølnir.