Katja

 is a Celestial Spirit Mage who owns the Celestial Spirits, Nico and Caelum.

Appearance
Katja is a slim young girl, with short blue hair and brown eyes. She wears a short whitish blue dress. She bears a strong resemblance to Wendy Marvell.

Personality
She cares deeply for her Celestial Spirit, Nico, as it is shown when she tells it to escape if it is frightened.

History
Katja is a descendant one of Will Neville's disciple. Except of knowledge about using Celestial Spirit Magic she inherited the Anti-Link Magic, which is located on her body in the form of magic seal.

Key of the Starry Sky arc
Katja is seen carrying Nico in front of a tree. She wonders about how long would the tree live. A man is then seen running up and warns Katja not to wander off, and she tells Nico to escape if it is frightened.

She is later seen inside a cathedral when Lahar and Doranbolt comes to visit her. She and Doranbolt had a few talk regarding a girl who 'died' seven years ago who appeared to be Wendy Marvell. Later she summoned Caelum and Doranbolt was amazed because she can summon two spirits at the same time. However, their small talk was interfered by Racer who states to destroy the vessel.

She is later seen running with Lahar in a hill. Just then Racer and Doranbolt arrived with the latter telling her to run. She is later saved by Doranbolt who managed to accept the stab from the red knife wielded by Racer. However the link markings on her body disappeared and she lost her ability on doing Celestial Spirit Magic. She later explained to Doranbolt to live a new life and forget about the past.

Magic & Abilities
Celestial Spirit Magic: This magic allows her to summon a Celestial Spirit. Formerly, she owns 2 silver keys and has a great mastery over it. She also has the ability to maintain Nico to their world, possibly hinting her magic power.
 * Multiple Summon: She can summon Caelum and Nico simultaneously with the help of her magic power.

Equipment
Her basic items are her Celestial Spirit Gate Keys, she has 2 known silver keys.

Silver Keys
 * The key to Nico: Summons Nico.
 * Gate of the Chisel Key: Summons the Chisel, Caelum.