An incarnate of Iðunn (or Idun); Goddess of Youth and keeper of orchards.
Foreshadowing: She's called the 'constant goddess' by Olaf in season one and two. For the Norse gods to exist on earth, there must always be an Idunn. So when Helend dies, the spirit of Idunn 'jumps the queue,' as Ingrid put it, and possessed the next goddess in line: Gaia, who would have otherwise become Frygg or Papatuanuku. Olaf also mentions that it always ends badly for her when Idunn meets Braggi. Helen is killed shortly after she meets Anders, and Gaia leaves the country because of the guilt from being attracted to him while still in love with Axl.
Killed Off for Real: Is shot in the heart by Natalie after the latter breaks into Anders' apartment.
A hospital nurse in her first year after training, and she’s also Axl and Zeb’s flatmate. She is also the daughter of a Maori Goddess and the Norse God Tyr; Currently the living incarnation of Iðunn (or Idun).
Meaningful Name: In Greek mythology, Gaia is the goddess or personification of Earth.
The Maori God of food and Gaia's older half-brother.
Martin Larson/ Heimdall
Heimdall is the Norse god of foreknowledge, the one who sees and hears all and can open the door to any realm. He also happens to be the Frygg's older brother.
Beware the Nice Ones: As Heimdall, he can use doors to teleport anywhere in the world, as well as send anyone to wherever he wishes. Olaf repeatedly warns Mike about going after Martin, since he could theoretically send Mike into the middle of a war zone if he so chooses.
Big Brother Instinct: He does his utmost to keep Mike from finding his sister, since he's not the true Odin.
More literally, he can sense when Hanna is in danger. As Michelle found out when he took a hammer to her skull.
Dangerously Genre Savvy: He knows how Mike's powers work, and refuses to fall for Mike's attempts to get him to 'play'.
Killed Off for Real: Martin's role in the Agar calls for him to die so that he can serve as the sentinel on the Bifrost.
Power Incontinence: Martin's human brain can't handle the information overload from being Heimdall, and is in therapy.
Remember the New Guy: He's been popping up in and out of the show through season three. Most notably, he dropped Axl back at Derrick's hometown to fix his problems, let Gaia into Anders' flat so Idunn and Braggi could consummate their love, and convinced Ty to be honest to Dawn about his powers.
Wife of Odin. Foremost Norse Goddess. Queen of Asgard. Basically, she is the reason the Johnsons have been questing. She's also the younger sister of Martin/Heimdall.
Broken Bird: Her relationship with her father is non-existent at best, she's personally responsible for taking care of her mentally unsound brother, two divorces...
Failed a Spot Check: Zeb wonders why none of them could figure out that maybe the Norse goddess of marriage would work in something related to the wedding industry. In this case, a bridal shop.
Screw Destiny: Before Martin interrupts her conversation with Michelle, she implies that she's in full agreement with 'taking Frygg out of the equation' since killing Odin (whoever he is) will be disastrous for all of them. She also had the same reaction when her father told her that she had to sit and wait for Odin to come to her, even if he wasn't going to come at all.
It's also heavily implied that she knew that Mike wasn't really Odin at all, but kept seeing him because of the actual connection they had, as opposed to the Red String of Fate that bound her to Axl/Odin. Once the fate of the world became at stake due to Jorgammund stirring, she sacrificed her happiness and chose Axl for the good of the world.
You Look Familiar: Frygg is played by the same actress who played Fem!Axl in his genderbent episode. When Mike sees her for the first time, he does a Double Take.
Axl and Gaia's flatmate.
Butt Monkey: Started out as comic relief. By season three, he's one of the first people Axl goes to when he needs help.
Crouching Moron, Hidden Badass: He's been reading up on all the Norse mythologies and stories, which lets him intepret some of the stranger events for Axl.