OVA
Description
Dimitrie Vatler serves as Duke of the Ardeal principality within the Warlord's Empire and is a direct descendant of the Lost Warlord. His vampiric power nears Primogenitor level, amplified by consuming two second-generation vampires.

He possesses blonde hair, blue eyes, and a handsome appearance consistent with a man in his mid-twenties. His signature attire features a white blazer over a white vest, a lavender long-sleeved shirt, a dark blue tie, and brown shoes. His demeanor transforms drastically in battle, often revealing a vicious smile filled with combat anticipation.

Vatler is a pleasure-seeking individual primarily driven by boredom and a craving for conflict. His morality remains ambiguous, with actions frequently aligned towards personal entertainment rather than clear loyalties. He is a battle maniac, fascinated by displays of power and strong will, especially in opponents who defy destiny through any means. This motivates actions like sheltering terrorists targeting him merely to alleviate tedium.

Fifteen years before the main events, he participated in the wipeout of the Black Death Emperor Faction, killing its leader. He later arrived on Itogami Island as ambassador extraordinary and plenipotentiary, granting him diplomatic immunity from local authorities.

Vatler's relationships are complex and often strategically motivated. He proclaimed love for the previous Fourth Primogenitor, Avrora Florestina, though its sincerity is questionable given his later defiance; he may have used it as a pretext to approach Kojou Akatsuki. His primary obsession shifted to Kojou after Kojou inherited Avrora’s blood and power. This fixation involves monitoring Kojou’s development, relationships, and potential as a source of thrilling conflict. Upon meeting Yukina Himeragi, he framed her as his "love rival," positioning her as a competitor for Kojou’s attention. He showed limited interest in Sayaka Kirasaka during her observation duty, finds amusement in Natsuki Minamiya despite her past disdain, and maintains formal but amicable diplomatic exchanges with La Folia Rihavein.

Vatler possesses standard vampiric traits: superhuman strength, speed, reflexes, durability, and potent demonic energy capable of exerting physical pressure. His signature ability is summoning nine snake-shaped Beast Vassals, each capable of natural disaster-level destruction. These include familiars such as Manasvin, Utpalaka, Sagara (manipulating water and extreme pressure), a thousand-headed serpent, Upananda, and others designated numerically or by names like Vasuki. He can fuse Beast Vassals, for example combining Manasvin and Utpalaka into the more powerful Shakara.

Across story arcs, Vatler consistently seeks to instigate or observe high-stakes battles. He orchestrated the Nalakuvera incident intending to combat it himself, though Kojou ultimately destroyed it. Following this, he established a permanent consulate on Itogami Island. His actions frequently serve to test Kojou’s abilities or provoke reactions from those around him, driven by his desire to witness the resolve and tactics of powerful individuals.