Gunilla

Gunilla was the demigod daughter of Thor, captain of the Valkyries and one of the thanes of Valhalla. She has lived in the hotel for 500 years by the time Magnus Chase arrives. She was brutally killed by Surt at the end of the book, and has not been seen since.

History
Gunilla died in the 16th century, roughly 500 years before, after which she was promptly taken to Valhalla, where she would eventually become the Captain of Odin's Valkyries and one of the thanes. At one point, she fell in love with a demigod son of Loki, who, however, ended up breaking her heart, as he turned out to be a spy sent by his father. As a result, Gunilla took to distrusting and hating all children of Loki.

The Sword of Summer
Gunilla is first seen in the dinner hall of Hotel Valhalla, where she questions Samirah al-Abbas about Magnus Chase's arrival. During the introduction ceremony she is seen sitting with other thanes. Gunilla then plays a sabotaged tape of Magnus's death to purposely get Samirah fired. Gunilla is seen after the trial, looking not even the most smug.

Personality
Gunilla seems to be a very strict and militaristic person; she distrusts Sam, asking if Magnus was 'one of her father's spies'. She is also very serious, threatening Magnus that she would kill him if he betrayed Valhalla. Probably referring to Samirah as the two had been friends.

Appearance
Gunilla is a tall, burly eighteen-year-old with pale blue eyes, and snow-blonde hair braided down her shoulders. According to Magnus, she is 'big enough to play power forward' and wears a bandolier of ball-peen hammers over her Valkyrie attire and a golden hammer pendant around her neck.

Abilities
General Abilities=
 * Fighting Skills: As a daughter of Thor and Captain of Odin's Valkyries, Gunilla is an extremely skilled and formidable warrior, with roughly 5 centuries of combat experience. As a result, she managed to hold her own in a prolonged fight against Surt himself (along with her two Valkyrie lieutenants), but was ultimately defeated.
 * -|Einherji Abilities=
 * Enhanced Strength - after gaining a new einherji body, Gunilla gained a degree of superhuman strength, to the point that she could punch through most walls without much effort.
 * Einherjar Immortality - while within Hotel Valhalla, Gunilla, like any of the einherjar, could not die, and simply keept resurrecting from mortal wounds.

Trivia

 * Gunilla is a Swedish name, a variant of 'Gunhild', from the Old Norse name Gunnhildr, derived from the elements gunnr "war" and hildr "battle".
 * Gunilla somewhat resembles Clarisse La Rue from both of the Camp Half-Blood series.