The story takes place in 810 and Christianity was very rare in the north. The use of Thor's hammer as a pendant is used after the the north was Christianized around year 1100 and is believed to have been used by believers of asatru to show their beliefs. Similar to how many Christian's use the cross today.
Due to the severe drought in Sweden during 2018, the crew were not legally able to light fires outside. Therefor any instance of fire light seen outside was faked with LED-panels.
Second Swedish viking film in 2019 featuring Ralf Beck, the other being Draug (2018). Both films features Beck's character complaining about the smell of the draugr.