Doranbolt & Katja vs. Racer

 is a fight that takes place during the Key of the Starry Sky arc.

Prologue
After doing extensive researching, Doranbolt and Lahar visit a church in the countryside. There, they encounter a young Celestial Spirit Mage with the name Katja. Lahar explains why they are present in the area and begins to look around the church. In the meantime, Katja summons Caelum to protect the church while she speaks to Doranbolt. Suddenly, while in the midst of a conversation, Caelum detects a stranger.

Battle
While attacking a person from outside, a figure strikes Caelum and destroys his metallic body. Katja is attacked next but luckily, Doranbolt grabs her and carries her away before she can be struck. However, the figure continues to attack them causing Doranbolt to repeatedly move around the church, this way neither he nor Katja can get injured. Their attacker is revealed to be a member of the Reborn Oración Seis, Racer. Racer states that he must destroy the vessel and grins, while the ruby dagger and the red lines on his outfit emit a glow.

Doranbolt releases Katja and tells her that she must flee with Lahar; though reluctant, she does as she's told. While she runs away from the church with Lahar, both Doranbolt and Racer begin their fight. Their battle quickly ensues to the garden outside where both begin using their unique speed-related Magics against each other. However, Racer is able to easily outmatch Doranbolt. Doranbolt quickly devises a plan based from the information he's gathered; since Racer apparently can only move from one end to the next, he should intersect the Dark Mage's attacking line with Direct Line. Doranbolt attempts this plan but ultimately defeated; he attributes this failure to having done nothing but drink for seven years.

As night begins to fall, Katja and Lahar finally relocate to a large tree out in the fields. They converse briefly, with Katja even revealing a personal secret about herself, though they are soon interrupted with the arrival of Doranbolt. He tells Katja to leave, though calls her Wendy instead. Soon after, he collapses and reveals Racer behind him. Racer quickly knocks down Lahar and, despite Nico's attempts to stop him, pins Katja to the tree. He pulls out his ruby dagger and as it glows, he attempts to stab her, thus activating the Anti-Link. Doranbolt takes the hit instead, but in the end, Katja remains the only one affected. A seal cursed upon her reveals itself but quickly dissipates. Racer, pleased that his plan was a success, leaves the scene as Doranbolt and Lahar rush to the Celestial Spirit Mage.

Aftermath
Katja is physically uninjured, though her Magical Abilities disappear almost immediately; this includes Nico, who is returned to the Celestial Spirit World. Doranbolt is disappointed with himself that he has failed to protect Katja, though she says otherwise, instead telling him that he actually saved her from a terrible curse. This causes him to cry a tear. Lahar tells him that he should move on from his mistakes in the past. Doranbolt, who agrees with him, gets up and proudly declares his name.