Kayoukazen of the Mourning Moon

Kayoukazen of the Mourning Moon is a ritual invented by Ainz Ooal Gown whilst he was vacationing in a dark elf village in the Elf Country.

Background
The ritual was a term that was crafted by Ainz to test his interaction with the dark elves. It was basically invented as a period of mourning. The name “Mourning Moon” was from words Ainz heard at the company he worked in. It held the meaning of the month of the date of a loved one’s death and the word “Kayoukazen,” was a word coined by Ainz, because it resembled something in the dark elf vernacular.

According to Ainz this month is the time for those to pray for the tranquility of the dead. According to supposed practice, those undergoing the ritual should avoid places that are too cheerful, like a party, for the time being and to forgo food and drink. Though this was to avoid crowds and speaking to the elders to prevent his cover from being compromised and also to explain why Ainz did not eat.

The Half Elf God-kin Arc
Ainz Ooal gown going under the persona of Ain Bell Fior settled in the elf tree that the villagers provided him, Aura and Mare, Ain was visited by a female dark elf who brought the family a dish that was the morning and evening meals. The dark elf tried to avoid speaking to him, as unknown to Ain word had spread about Ain's unique etiquette and none of the villagers wanted to embarrass themselves by failing to respond formally, but Ain managed to ask a question to her before she could disappear. He used the opportunity to explain the maed-up ritual to her, though he was expecting that the dark elf would not know about it. Contrary to his expectation, the dark elf claimed that she was familiar with the ritual to his surprise. Ain took her words at face value, unaware that she bluff him to give him a satisfactory answer to hide her own ignorance of dark elven culture from the city. Nonetheless the misunderstanding allowed Ain to go through the village without interruption for his plans and also permitted the village to save face.

Abilities and Powers
Unlike most rituals that appear in Overlord, this ritual is merely a piece of fiction for the purpose of infiltrating dark elf society by its maker.

Trivia

 * Incidentally, the reason Ainz knew the words “Mourning Moon” wasn’t because he learned them at the company he worked for, but because it was the name of a Skill in YGGDRASIL.
 * When Ainz heard that the dark elves had a similar name for the ritual he was worried that in the worst-case scenario it would be the name of some evil ritual.