Loki
Loki first appears in the manga in chapter 1. At first Loki appears to only be a minor character, but in fact turns out to be the main antagonist by the end of the manga. We are told that Loki is half Vanir and half Aesir, and so is bullied by his peers. When asked about this, Loki will only say he is well. The next time you see Loki is the last page of chapter 7, snickering to himself over the gathering of the Einherjar and his belief their efforts are worthless and everyone will ultimately perish. In chapter 9, while Hrist attempts to annihilate Arngrim, Jelanda and Lucian after they refuse to obey her, Loki teleports Lucian to safety, to Asgard. Loki manipulates Lucian's emotions and convinces him that in order to help Lenneth he must aid him in obtaining the Dragon Orb. Lucian asks why Loki would help him and Loki partly admits that, long ago, Odin sealed his power and he wishes it back. When they enter the room containing the Dragon Orb, Loki abandons Lucian to defeating the Orb's guardian Sleipnir. Loki is then able to steal the Dragon Orb. With his power restored, Loki's appearance changes. With Lucian's usefulness ended, Loki murders him. In chapter 10 Loki visits the Vanir. He asks to be their ally but Surt, King of the Vanir declines. Loki brings in the evil dragon Bloodbane and ice wolf Fenrir. It is not clear if Loki attacks Surt or the Vanir, but he is pictured charging into Valhalla riding on Fenrir. Frei is there to confront him and sends out two Einherjar, whom Loki easily defeats. Frei has the opportunity to attack him, but Loki survives it and kills Frei in one blow. Loki then advances to Odin. Both are armed with relics and Odin is able to withstand Loki's attacks for some while. Ultimately Loki proves more powerful and defeats him. In the final chapter Lenneth Valkyrie confronts Loki. Loki mocks Lucian's death, inciting Lenneth to attack. Loki attacks with the Dragon Orb but when the dust clears and Lenneth is alive, Loki is shocked. He regains his composure and attacks Midgard with the Orb instead, fulfilling the prophecy of Ragarok. But Lenneth undoes his destruction with her new powers of Creation. Lenneth then slays Loki, says he is a very sad child, and absorbs his soul, much like an Einherjar.