Encyclopedia Entry:
A demonic knight with a grotesque figure, its head has been severed from its body. It inhabits the demon realm. Because of its identifying feature, it’s also known as the “headless night.” They are the prized avant-guard of the demon lord’s knights. They are extremely loyal, and possess exceptional military prowess. In the schematic shown here, they hold their head with their left arm, but most of the times they appear, they put their head on their body, so it’s often hard to even realize that they’re dullahan.
Men’s spirit energy is what fuels them, but they don’t aggressively attack. They are very intellectual. They store all of they’ve ever collected inside their bodies, and use their head as a lid, so they can get by normally even with a very low amount of spirit energy collected. However, being dullahan, their heads come off very easily. When this happens, their pent up desire, emotion, and true intentions are spilled out along with all the energy. Because of this, when their head is in place, they are stubborn and intellectual, but once the head comes off, it’s a whole different ball game! They change to having a meek, lustful personality. If one ever encounters a dullahan, be sure to take advantage. Knock of their head, and you can end the fight. However, the spirit energy will spill out, and she’ll become hungry. As noted above, her personality will change and she’ll probably assault you right then and there.