- Name: Jack D'Avare
- Occupation: Mercenary
- Guild: Sovereign
- Weapon: Dual swordsman
- Element: Fire
- Family: n/a
Jack is a flirtatious, enigmatic mercenary in Sovereign. He is known for his carefree, playful attitude and light-hearted humor.
He is the connoisseur for his apprentice, Melissa. Their relationship involves Jack constantly calling Melissa his "cute apprentice," much to Melissa's annoyance. Melissa is often annoyed with Jack's playfulness and teasing, but they still maintain a strong relationship as mentor to protege. In episode five, Jack is shown to blame himself for Melissa's unconscious state, and Kyle had lashed out on him, telling him he had to stop being so careless and irresponsible. Although portrayed as someone who doesn't take things seriously, he is shown to be by Melissa's side whenever she is in the hospital, and feels bad about the stress and burden Shaun puts on himself.
Jack's past is very troubled and is detailed in the episode Jack's Story. He was still a one-handed swordsman when he grew up with his best friend Rose. The two were very close and formed an intimate relationship during mercenary training, but were separated when Jack went to Sovereign and Rose went to the guild Seraph. Rose would also tease Jack about how she will be able to protect him once she completes her mercenary training, as Seraph specializes in defensive techniques. During the Great War, many mecenaries from the guilds were hired to fight for the Royal Court. Jack sees Rose for the first time in over a year when he ends up in the medical tent for an injury tending to the injured. While Rose is healing him, Jack overhears a soldier refusing to send a soldier to find a frantic mother's son who was left behind in the battlefield. Determined to save him, Jack gets up mid-way through his healing and promises the mother he will find the boy, who he learns is named Oscar. Rose reprimands him and tells him not go because it is dangerous, but Jack goes anyway. Jack ventures into the ruined village at the site of the last battlefield in search of Oscar, who he finds huddled behind a pile of rubble. As they begin their return to the campsite, they are attacked by a mercenary hired by the enemy. Jack engages the mercenary in battle. Mid-way, however, Oscar throws a extremely well-aimed pebble at the mercenary that hits him in the face. Livid, the mercenary charges toward Oscar, who, in fear, is frozen to the spot. Jack springs in front of Oscar to take the hit of the mercenary's sword, but Rose appears out of nowhere and takes the hit instead. Jack is in shock when he opens his eyes to see the mercenary's sword plunged through Rose's now bloodied body. Rose uses the last of her strength to eliminate the mercenary. Jack holds her in his arms in tears as she takes her last breath and rain begins to fall. Since then, Jack keeps a rose in his mouth in honor of her, uses her sword in his other hand as a shield, and visits her grave annually on the anniversarry of her death.
Jack was buried alongside his childhood friend, Rose.
Eruption: This attack was first seen in Jack's side story - Season 1, Episode 5.5. It is a fiery ground attack in which magma and volcanic rock emerge and explode on the enemy.
- Crimson fury burn... eruption!
Rose: Rose and Jack were childhood friends, although romance between them had been hinted. Rose sacrificed herself for Jack. In honor of her, Jack wears a rose in his mouth, uses her sword in his other hand as a shield, and visits her grave every year.
Melissa: Jack is Melissa's connoisseur. The two have a comical relationship as Jack is lazy, playful, and laid-back while Melissa is strict and serious. He likes to flirt with her and often calls her his "cute apprentice." It is shown that Jack cares a lot about the well-being of Melissa, as he is always by her side when Melissa ends up at the hospital after being injured.
Shaun: Jack first sees Shaun when Shaun runs into the forest and starts attacking everything with ice when he is upset for not being able to be like his father. He is deeply touched by this and has great respect for him.
- In Jack's story, Jack's love interest is named Rose. Jack and Rose are the two lovers from Titanic.
- The character concept for Jack came from the flirtatious character Zelos from the RPG game Tales of Symphonia.