Lucian

Lucian is a swordsman who has ties to Platina, Lenneth's human vessel. He plays an important role in returning Lenneth's memories and getting the best ending.
 
Lucian and Platina grew up in Coriander, a poor village who has resorted to selling their daughters for money. One day, Lucian saw men in black robes who visits Platina's home and recognizes them as the traders who bought his sister. He decides to run away with Platina. As they entered the Weeping Lily Meadow, Platina inhaled too much of the poisonous pollen and died. Lenneth's soul is then released and Lenneth returns as a Valkyrie. 
 
A few years later, Lucian moves to Gerabellum and joins a group of thieves to help the inhabitants of the slums to survive. The group includes Barren, Rusty, and Claire. Claire has feelings for Lucian though Lucian could not forget about Platina. 
 
Some time later, Barren made a mistake of stealing from a nobleman. He was caught and tortured to death and the nobleman orders a purge of the slums. During the purge, Lucian was killed and was taken by Lenneth as an Einharjer. Lucian was shocked at Lenneth's resemblance to Platina but Lenneth's memories as a human has been sealed away, thus she does not understand Lucian's surprise. 
 
If the player decides to send Lucian up to Asgard before Chapter 7, Lucian will confide in Lenneth about her similarity to Platina. He tells Lenneth about his childhood times with Platina and asks Lenneth to remove her helmet to see her clearly. He then comments that Lenneth looks exactly like Platina but decides that she is a different person. 

If Lenneth's Seal Level is low enough, Frei and Loki will meet Lucian in Asgard. Lucian confesses his feelings for Platina and Lenneth, and Frei explains the concept of Valkyrie transmigration to Lucian and further explains that Lenneth's memories are sealed to prevent them from interfering in her duty as a Valkyrie and only Odin and Freya can remove it. 

Loki then tells Lucian about how to have Lenneth break the seal on her memories by herself. Loki tells Lucian to use the Water Mirror to contact Lenneth and give her one of Platina's earrings, and tells her to find the other which is at Platina's grave in the Weeping Lily Meadow. This gives Loki a chance to steal the Dragon Orb and blames it on Lucian. Loki then kills Lucian to appease Odin. 
 
If in Chapter 8, the player decides to visit the Weeping Lily Meadow, Lenneth will find Platina's other earring and breaks the seal on her memories. Odin senses the breaking of the seal and invokes the Sovereign's Rite to have Hrist take over as Valkyrie instead. Arngrim, Mystina, and Lezard works together to restore Lenneth as the Valkyrie, and Lenneth confronts Loki in Asgard. 
Loki used the power of Gungnir and the Dragon Orb to defeat Odin and destroy the world. Lenneth gains the power of Creation and defeats Loki and restore the world. She also brought back Lucian and they happily reunite.