Epigoni

Ebynogoi (エビノゴイ) is an artifact class magic item which allows the user to open a locked door.

Description
Ainz Ooal Gown has one such magic item in his possession.

Appearance
It looks like a piece of hand-held board.

Abilities
It enables the user to open doors that would require the skills equivalent to a level ninety thief.

Trivia

 * Ainz used this magic item on the treasure vault door in Feo Berkana in order to gain access to the treasure stored in it.
 * Despite its pronunciation, it's actually written as 七門の粉砕者, meaning the destroyer of seven doors which explains that it can only be used seven times.