Bringing about the end of the world as it is known
About Herald of Ebbonacci
The Herald of Ebbonacci serves the Wormlord of the Underworld, but like most important servants of the Eldest Elemental Evils carries a Ward of Avraenasa that renders his alignment and true thoughts undetectable to anything short of a daughter of the morning.
Some sages who specialise in Eldest Elemental Evil lore (and who have not yet been devoured as the price of their knowledge) might be able to recognise the brooch which he carries as a servant of Ebbonacci for what it is, or the Ward of Avraenasa pendent, if seen, but otherwise there seems to be little remarkable about the Herald of Ebbonacci.
Knowledge such as that of the names Avraenasa or Ebbonacci is exceptionally rare, as such knowledge tends to lead to the destruction of most possessors. Even deities have problems handling it, and if they need to know such information generally remove it from their memories as soon as possible afterwards, just to be on the safe side.
Outside of the daughters of the morning, only a few dragon and succubi sages (or worshippers of Eldest Elemental Evils) can apparently handle such knowledge safely.