Sindri and Brok help Kratos and Atreus during their adventure. In their forge, they can improve the weapons and equipment of the Spartan and his son, as long as they are given the necessary materials.
In Norse mythology, Eitri (or Sindri) is a dwarf and the brother of Brokkr.
According to Skáldskaparmál, when Loki had Sif's hair, Freyr's ship Skidbladnir and Odin's spear Gungnir fashioned by the Sons of Ivaldi, he bet his own head with Brokkr that Eitri would not have been able to make items that matched the craftsmanship of those mentioned above.
Eitri began working in his furnace while his brother was working the bellows, but a fly (sometimes thought to be Loki himself) began stinging Brokkr, trying to stop him and spoil the items.
Eitri succeeded in making the golden boar Gullinbursti, the golden ring Draupnir, and the hammer Mjöllnir that made his brother win the bet, even if its handle was shorter than it should have been.
The near exact opposite to his brother Brok, Sindri is polite, well-meaning and educated. He treats every piece of craft as an artwork that must be carefully handled, thus he pays very much attention to detail and operates with precision.
However, Sindri can be extremely squeamish with anything that could be considered unclean. He exaggerates getting sick with handling any weapon that was recently used to kill. Even the mention of something repulsive, like Odin's request to make a craft to house Mimir's other eye and the venture into The World Serpent stomach, made Sindri vomit.
Sindri is also much more emotional than his brother, getting saddened upon hearing about Faye's death and expressing visible frustration with his brother. He was also visibly hurt after Atreus mocked his complaints about his brother. Thankfully however, Sindir didn't hold a grudge and was able to forgive the boy.
Like Brok, Sindri also expresses regret for forging Mjölnir for Thor, as the god used it for evils such as genocide against the Jötnar.
Powers and Abilities
Master inventor: Sindri is a skilled inventor, especially in weaponry, armor and other war items but unlike his brother, Sindri is not entirely focused on weaponry. He can make other kind of things such as the Sky Mover, an "elevator" to the top of the mountain and mistletoe arrows. With the necessary materials, Sindri can make or improve items for Kratos and Atreus. He and his brother, Brok had created the Mjolnir, one of the most powerful weapon in Norse mythology and Leviathan, a powerful magical axe with ice magic. Both weapons can go back into the owner's hand if they wanted.
Magic: As a Dwarf, Sindri can use magic very effectively. Mostly, he uses his magic to enter The Realms between Realms in order to enter any places in the nine worlds and make himself invisible, thus allowing him to avoid enemies. That explains why Sindri and his shop can appear anywhere in all the realms without getting into any trouble or challenges, but it doesn't seem to work on dragons. Sindri is also uses his magic on a dragon's tooth to make it capable of imbuing enchanted lightning to Atreus's Talon bow.
- Despite being dwarves, Brok and Sindri are still referred to as "the Huldra brothers", when the Hulder are an unrelated female species from Scandinavian folklore.
- Atreus brings this up to Mimir at one point, and Mimir implies the reasons behind this are not suitable to tell a young child.
- Sindri is quite germaphobic, as exemplified by his remarks of disgust at the blood on Kratos' weapons as well as continuously scrutinizing his brother for blacksmithing with his bare hands.
- In addition, Sindir may possess a form of haphephobia, the fear of being touched, as he reacts with fear when his about to be touched and finds it difficult to touch someone else, such as shaking hands, though most likely out of fear of getting unclean.
- In some of his dialogue, Sindri reveals the origin of his germophobia, stating that he once lived just as unsanitary as any other dwarf. It changed when he met a Vanir witch who, using her magic, discovered the multitude of tiny, unseeable "beasties" (microscopic germs and bacteria) that live on everything, and can make people sick if they get inside of the body.
- To this end, he states that he now only makes handles out of oak, as the witch told him it would stop the "beasties" from spreading.
- He and his brother were responsible for creating Thor's hammer, Mjölnir. Mimir claims that the two brothers were trying to make a name for themselves, but may have overdone it.
- In addition, Sindri mentioned that after Mjölnir was completed, both brothers found it very difficult to find new inspiration, among other things.
- He and his brother shared a brand that they used to mark their work, including marking Kratos' axe. When the two went their separate ways, they split the brand down the middle and each took half. Once reunited, they created a new brand.
- Sindri possibly had romantic feelings for Faye, Atreus' mother and Kratos' wife, as seen by his thinking that they had stolen the Axe, but soon learned that it was passed down and, as a result, decided to lend his help, even though it was unasked for.
- During the second encounter with Sindri, it is revealed that he possesses a magic bag of sorts that allows him to carry any multitude of items, regardless of its size or nature.
- He, along with Brok, also knew of Faye's true nature as a giant as well as Atreus's being half giant.
- In the traditional Norse myths, Sindri is alternatively named Eitri.