Sif

Sif is a friend of Thor's and The Warriors Three. She first appeared in Thor and appeared again in Thor: The Dark World. She is portrayed by Jaimie Alexander.

This version of the mythological Sif was created by Stan Lee and Jack Kirby.

Thor: The Dark World
"I had things under control!"

- Sif

''Sif is one of Asgard's most formidable warriors. Skilled and fearless, she's a trusted and faithful ally to Thor. During his banishment, Sif saw Loki's treachery and risked all to return Thor to Asgard…but on Earth, she saw that she had lost Thor's heart to another—the human Jane Foster. Now at the end of a long campaign to free the Nine Realms from strife, Sif seeks to rekindle her relationship with Thor.''

Sif traveled with the other asgardians to Vanaheim to stop the Marauders, who were causing a great damage around the Nine Realms. She and the others fiercely fight against Marauders. When Thor arrived, he easily defeated Marauders. The Marauders then called their best warrior, Korg. Sif allowed Thor fight the monster alone. Thor defeated Korg with one blow and the battle ended. She and the other Asgardians returned to Asgard to celebrate the victory. Tired of the parthy, Thor decides to leave but he is interrupted by Sif. Sif told Thor that she knew he was visiting Heimdall only to know how Jane was.

After the Malekith and his troops, Sif attended the mass funeral in honor of all the fallen soldiers in battle. The next day, she was summoned by Thor to devise a plan to prevent other attack from Malekith to Asgard. Thor then sent her to liberate Jane from Einherjar Guards and so take Jane to the Dark World and allow Malekith remove the Aether from her. Sif helped Jane to free from the guards. When Thor and Loki was preparing to go to Svartalfheim, she threatened Loki with kill him if he ocurred to him betray Thor.

Finished the battle against the Dark Elves, Sif and Volstagg went to the Collector's Museum, to hand over the Aether because it is dangerous to have two Infinity Stones in one place. Sif warned Tivan that he must protect the Aether at all costs.

Agents of S.H.I.E.L.D.
As a result of the attack of the Dark Elves, many prisoners of Asgard escaped including Lorelei an asgardian sorceress. Loki disguised as Odin sent Sif to capture Lorelei. Upon reaching to Earth, Sif finds Coulson and his team, who decide to help her.

Meanwhile, Sif and Lorelei talking, it was revealed that Lorelei used her powers to seduce the lover of Sif. After many problems, Sif capture Lorelei and return to the dungeons of Asgard. Before leaving, Coulson aks Sif that she did not tell Thor that he is still alive, Sif accepts the request and return to Asgard to confine Lorelei for her crimes.

Sif was sent to Earth by Odin to stop a Kree who had gone to Migdard with unknown reasons. She fought fiercely against the Kree, however Vin-Tak used a device to erase her memory. Later, she met with a group of teenagers, one guy tried to seduce her, causing her to hit him. The police managed to stop her, with the promise that they would bring Kava to her. Coulson and his team arrived to Faro, Portugal; they told her that she and S.H.I.E.L.D. worked together in the past.

Sif, Coulson and May walked around the place where she and Vin-Tak had fought earlier; Sif said not remember anything of what happened. When May asked her about what she remembered of Thor, she could give no account, but admitted that the name alone made her want to smile. Meanwhile, Skye and Bobbi Morse had a encountered with Vin-Tak. That night, they managed to capture him in Chaves. Sif demanded answers from the kree; Vin-Tak told her that he used Truncheon to erase her memory so she would not interfere with his mission. He then used Truncheon to restore her memory.

Vin-Tak informed the Asgardian that he went to Earth to destroy all kree experiments, called Inhumans. Suddenly the floor began to tremble, then Sif and Vin-Tak realized that Skye was one of those experiments. Sif pursued Skye and ordered May to hand over Skye. Cornered, Skye decided to shoot herself to prove that she was not a monster. Later, Sif took Vin-Tak and returned him to Hala.

The Avengers: Earth's Mightiest Heroes
Sif is a young woman who was hails from Asgard. There, she grew up alongside Loki, Thor, and Amora the Enchantress.

She was seen leading the Valkyries alongside Brunhilde against a trio of Frost Giants who had besieged both Giant Man and an unconscious Wasp. Sif assisted in several battles during war against Loki, but was defeated. She was later present when Odin took his place on the throne, and cheered for the Avengers alongside her fellow Asgardians.

While Thor stayed in Asgard, Sif overheard how Thor missed Jane Foster, a mortal from Midgard. She interrupted them remarking Thor that he should return to Midgard. Thor went away after Odin arrived and reported that Surtur was missing from Muspelheim and the Warriors Three reported that something was troubling Heimdall, so Thor went to find out the cause.

She was present when Odin summoned Beta Ray Bill who was holding oned Beta R. She attacked without hesitation the Korbonite, but was easily defeated. He was then taken hold by Odin and summoned Thor. Bill explained his backstory and Sif offered to help him to save his people from the Fire Demons and offered her sword after Odin rejected the proposal of Thor giving Mjolnir to him and suggested that they have Eitri, a dwarf, make a hammer for Bill.

After Bill acquired the hammer Stormbreaker, they went to the Skuttlebutt, currently being attacked by the Fire Demons. While Thor and Bill battled the demons, she went into the ship and activated the system of the Skuttlebutt, and ordered the ship to go after the Enchantress who was commanding the Fire Demon army, but was stopped by the ambush of more demons. She went to the place of the sleeping pods where the Korbonites rested and fended off the Fire Demons, until they vanished after Thor and Bill defeated the Enchantress. After they arrived at the Skuttlebutt, she offered to Bill to protect the Korbinites, but Bill refused since he thought her duties lied elsewhere. She bade farewell to Bill and left with Thor apologizing to him for earlier.