Valgren

Valgren (バルグレン) was a dragon that was summoned by Stride Vollachia roughly four decades before the start of the series and a year after the end of the Demi-Human War. It was reduced to ash by the Divine Dragon Volcanica.

Appearance
Valgren was a black-scaled three headed dragon. Each of its heads were lined by rows of sharp fangs, and its wings had claws on them. Its size spanned over tens of meters. It had two short legs compared to its size and arms with wings attached to them.

Personality
Valgren was a vicious, blood-crazed dragon, consumed by hatred. It's alluded that the souls inside of it can wrest some level of control over the dragon. Its three heads are mentioned to fight with each other when tearing apart its prey.

History
Around 40 years before the main story, Valgren was summoned near the southern Lugunican border with Vollachia, in the city of Picouttate, by Stride Vollachia. At that time, Stride was a Sin Archbishop of the Witch Cult, representing Pride. In order to summon the Black Dragon, Stride used a fang and soaked it in the blood of twenty human sacrifices, allowing him to bring the dragon to Picoutatte through some means. Out of the 500 knights sent to kill it, 50 were killed and 200 were annihilated before Valgren itself died. To cover up the fact that a dragon was controlled by someone in Lugunica, Valgren was referred to as an evil dragon. In the end, Valgren ate Stride and his wife, Melinda, with its three heads tearing them both to pieces and feasting on their bodies.

Following Stride's death, Valgren was confronted by Wilhelm van Astrea and Grimm Fauzen, who both dealt a great deal of damage to the dragon. During combat, Grimm and Wilhelm were both seriously wounded and could barely continue the fight. Just as the battle was about to close on a disastrous end, His Majesty the 40th King of the Dragon Kingdom of Lugunica Gionis Lugunica appeared in the city, and with him, the Divine Dragon ascended from the sky above. In a couple of minutes, Volcanica scorched Valgren away, put out the raging fired and healed all the damage the Evil Dragon had done, marking the end of the Subjugation of the Evil Dragon.

Abilities
Fire Breathing: Valgren was able to breathe fire. Breathing fire was its most common ability as it used fire to burn Picoutatte and its citizens. It burned with a pale green light, and it was hot enough to burn stone.

Great Power: Valgren was able to use a combination of its fangs, tail, and claws in close-quarters combat. Because Valgren's attacks were so powerful, even Wilhelm van Astrea attempts to parry them caused both of his shoulders to creak and some of his muscles to rupture, and just one of its blows was able to incapacitate Grimm Fauzen.

Trivia

 * There is a song called the Subjugation of the Black Dragon made by Liliana Masquerade. She sang it the first time during Arc 5.