Magnus is a teenage einherji, a resurrected soldier in Odin's army, living in Hotel Valhalla. As the son of the Norse god Frey, he possesses glowing healing abilities rather than a natural aptitude for combat. He is loyal and highly sarcastic, supporting his friends while worrying about his uncle's dangerous alliances.

Sam is a Muslim Valkyrie who balances her mortal high school life, flight lessons, and duties to Odin. As a daughter of Loki, she possesses shape-shifting abilities that she actively avoids using. She faces intense pressure when her godly father arranges a marriage for her, threatening her relationship with her mortal betrothed.

Alex is a newly deceased einherji and a child of Loki. Identifying as gender-fluid, Alex shifts between female and male identities (though predominantly female). She possesses a highly guarded personality resulting from a difficult upbringing and embraces her inherited shape-shifting powers while fiercely rejecting her godly parent's influence.

Loki is the Norse trickster god of chaos. Bound in a cavern with venom dripping onto his face as punishment for past crimes, he often projects himself into visions as a suave, well-dressed figure. He uses his manipulative abilities to control his children and strikes dangerous bargains with mortals and giants to secure his release.

Blitz is a dwarf with a passion for fashion and crafting. Since sunlight turns dwarves to stone, he wears custom-tailored protective clothing outdoors. He is a steadfast companion to Magnus and Hearth, using his problem-solving skills and magical tailoring to aid their quests.

Hearth is an elf who relies on sign language to communicate and practices rune magic. He carries deep emotional pain from his childhood in Alfheim, having been shunned by his father for his deafness and blamed for a tragic family accident.

Amir is a mortal teenager who works at his family's falafel restaurant and is betrothed to Sam. He experiences profound confusion regarding Sam's sudden revelations about her life as a Valkyrie and the existence of Norse deities, but his love drives him to understand her world.

Randolph is Magnus's grieving uncle who lost his wife and daughters in a storm caused by the gods. Desperate to reunite with his family in the afterlife, he makes a dangerous bargain with Loki, putting him at odds with his nephew.

Mr. Alderman is Hearth's wealthy and influential father. He is an arrogant, status-obsessed elf who looks down on other species and demands harsh financial penance from Hearth for a past family tragedy.

Thor is the Norse god of thunder. He subverts expectations by sporting pigtails, gym shorts, and a heavy metal t-shirt while obsessively watching television. He relies on mortals to locate his missing hammer, which he mainly misses because he uses it to stream shows.

Thrym is an earth giant who strikes a bargain with Loki. He intends to marry Sam to secure Thor's hammer and establish a truce, ignoring warnings about Loki's long history of betrayal.

Thrynga is an earth giant and Thrym's sister. While she appears to go along with her brother's wedding plans, she harbors her own ambitions for power and plots to double-cross the trickster god.

Utgard-Loki is the king of the giants in Jotunheim. He runs an enormous bowling alley and tests Magnus's group through a series of skewed competitions, balancing his desire to stop Ragnarok with the need to appease his unruly subjects.

Inge is a hulder, a nature spirit considered a second-class citizen in Alfheim. She serves as a servant in Mr. Alderman's household, where she is forced to display her cow tail as a mark of lower status.

Annabeth is Magnus's cousin and a demigod daughter of the Greek goddess Athena. She deals with her own mythological troubles in New York but offers Magnus advice and connections to help with his oceanic problems.

Heimdall is the guardian of the rainbow bridge. He is highly uncoordinated and obsessed with using his magical ram's horn as a smartphone to take selfies across the Nine Worlds, often missing actual threats right in front of him.

Sif is Thor's wife, a goddess with long golden hair who resides in the Bright Crack palace. She distributes coupons for chain restaurants as rewards and has little patience for the chaos surrounding her husband's missing hammer.

Otis is one of Thor's magical goats. He attends therapy and attempts to provide Magnus with vital information regarding the location of his master's missing hammer before being silenced by an assassin.

The Careful One is a dwarf who hoards an immense amount of cursed gold. He uses a magic ring to build his fortune and relies on animal transformations to stay hidden from thieves.

Jack is the enchanted Sword of Summer. Capable of speech and independent movement, the magical blade acts as Magnus's weapon and companion, holding its own in combat and conversation.

Gellir is a Danish prince turned undead wight who guards a barrow tomb. Bound by rigid Norse democratic traditions, he must vote with his undead warriors before attempting to slaughter intruders.

Tiny is an enormous giant traveling to a bowling tournament in Jotunheim. He tasks Magnus and his friends with carrying his massive bowling bag in exchange for safe passage.