Soul Eater

Soul Eaters (ソウルイーター) are legendary undead monsters that were summoned by Ainz Ooal Gown for his war against the Re-Estize Kingdom. They appeared on the battlefield in the Katze Plains as mounts for Ainz and his army.

Appearance
Soul Eaters are skeletal horses with an aura that shines a light on their chest. They are beasts made out of bones, with tendrils of fog replacing their flesh and blood. The fog sparkled everywhere, pus yellow and emerald green.

Background
In the New World, it was stated that three Soul Eaters alone once appeared in a beastman city, killing over one hundred thousand beastmen. To the countries, Maruyama stated that their presence alone is enough to cause a national state level emergency.

Without at least a 3rd-tier magic caster present, even facing them was next to impossible. But at the same time, only someone or group of the heroic level can do anything, so its a crisis for all the surrounding nations to deal with.

Abilities
Soul Eaters has long-range attack skills with many uses. They can receive a temporary power-up buff for killing its target through the skill, making it hard to defeat. In other words, Soul Eaters are the kind of undead with an area-affecting ability. Soul Eaters could consume the souls of the deceased for sustenance while also growing stronger the more souls they ate. They radiated an aura of fear.

Also, they are capable of killing everyone who smelled its breath of instant death. When Soul Eaters appeared in YGGDRASIL, they were almost always on-level encounters. Therefore, chances of a player being downed by an instant death effect would only be one in a hundred or less. That was why a Soul Eater's special ability rarely got the chance to see use.

Trivia

 * Just like the Death Knight, they are looked upon by New World inhabitants as a legendary undead.
 * Five hundred of Soul Eaters were used as mounts for Death Knights and various Nazarick Guarders during the annual war between the Re-Estize Kingdom and the Baharuth Empire.
 * On the adventurer rating system, Soul Eaters have a difficulty rating estimated at 100 to 150. This would make them equivalent to a level 33 to 50 monster in YGGDRASIL.
 * Ainz is currently experimenting on whether or not the Soul Eaters could remain in the New World permanently through consuming the souls of their targets rather than the corpse.