Siegfried

Siegfried is a member of the Khaos Brigade's Hero Faction and the decendent of the Siegfired of the Nordic legends that was the first wielder of Gram. He is one of the top two swordsmen of the Khaos Brigade alongside Arthur Pendragon of the Vali Team, and is known as The Demonic Sword User, the Demonic Emperor, and "Chaos Edge" Sieg.

Appearance
A young man with silver-white hair.

Personality
Little has been mentioned of Seigfrieds personality besides that fact that he is a dedicated swordsman and the rival of Arthur Pendragon.

History
In the past, Siegfried worked for the Orthodox Church, and was trained in the same institution that trained Freed Sellzen. He is considered the best swordsman after Dulio Gesualdo, bearing the nickname "Chaos Edge" Sieg (魔剣（カオスエッジ）ジーク Kaosu Ejji Jīku), but he eventually left the Church and joined the Hero Faction, where he has a rivalry against Arthur Pendragon.

Birth of the Breast Dragon Emperor
Siegfried appears in Volume 6, talking with Cao Cao on the Old Satan Faction's defeat, asking if it is time for the descendant of the heroes to take action.

The Heroic Oppai Dragon
In Volume 7, he is seen discussing with Cao Cao on their next course of action.

He made his first official appearance in Volume 9, while he and the rest of the Hero Faction are at Kyoto, kidnaping the leader of the Youkai under the intention of using her as a substitute to open the Dragon Gate and summon Great Red. He later fought Kiba and Xenovia by himself and defeats them with ease after revealing his Balance Breaker. When Sun Wukong came, he attempted to fight the monkey but was defeated in one attack. He and the members of the Hero Faction were then forced to retreat.

In Volume 11, he came to the dimension created by Georg using Dimension Create and has a rematch with Kiba, resulting with the latter cutting off one of his Dragon arms. After the sudden appearance of Shalba Beelzebub who appeared with a kidnapped Leonardo who forcefully activated Leonardo's Balance Breaker, Siegfried and Georg take Leonardo and retreat.

In Volume 12, he and the members of the Old Satan Faction goes to Ajuka Beelzebub's hideout at the human world intending to form an alliance with Ajuka but was rejected, He then fought against Yuuto for the third and final time. During the fight, Siegfried injected the blood of the Original Satan which made his body undergo a demonification process where he transform into a monstrous spider and fused with his Demon Swords and Sacred Gear. With the new form, Siegfried easily overwhelms all the members of the Gremory Team, cutting Yuuto's left arm and injuring both his legs. The battle was overturned when one of Issei's Evil Pieces transformed into the Ascalon, allowing Yuuto to injure Siegfried. Siegfried finally lost to the latter after his strongest Demon Sword, Gram, left him and chose Yuuto as its new wielder as he received attacks from the Gremory Team with Yuuto dealing the final blow by stabbing him with both Gram and Ascalon. His body starts to crumble after that and when asked by Yuuto on why didn't he use the Phoenix Tears, Siegfried responds by saying that when using the doping of the Satans' blood, they cannot use Phoenix Tears as his body crumble to his death.

Powers & Abilities
Siegfried's Sacred Gear is "Twice Critical", a common Sacred Gear that Raynare mistook Issei to have possessed. Since it is a sub-species, instead of a gauntlet, it creates a Dragon Arm on Seigfried's back and doubles his power. Its Balance Breaker, "Chaos Edge Asura Ravage", allows him to have four Dragon Arms growing out from his back, with his power doubling for each. As a result, he has six arms in total (including his real arms) in his Balance Breaker form. He has all five Demon Swords: Gram, Balmung, Nothung, Tyrfing and Dáinsleif, and one sword of light in his possession.

Trivia

 * The Dragon Arm(s) created by Siegfried's Twice Critical are silver in color, the same color as his hair.
 * His current hair color is due to the training he received during his time in one of the institutions of the Church.