Master's Defender

Eraqus's Keyblade (エラクゥスのキーブレード) is a Keyblade used by Master Eraqus and Aqua in Kingdom Hearts Birth by Sleep.

After defeating Vanitas at the Keyblade Graveyard, Aqua returns with a comatose Ventus to the Land of Departure, which is now shrouded in darkness. There they find Master Eraqus's Keyblade, left behind where Eraqus was felled by Master Xehanort. Aqua uses the Keyblade to transform Land of Departure into Castle Oblivion, and takes the blade with her upon departure. Perhaps due to her unfamiliarity with the weapon, Aqua chooses not to use it in combat against Xehanort.

After being trapped in the Realm of Darkness and losing her own Keyblade to save Terra's body, Aqua is shown wielding this Keyblade as she wanders the dark realm.

Design
Master Eraqus's Keyblade has a smooth, cylindrical, grey shaft that tapers outward at both ends. It has a boxy guard, made up of two small, light grey boxes and copper rods. The base of the guard connects to the handle, and both sport several small indentations lining them. The teeth are in the shape of an "E". His Keychain is made of several simple chain links and its token is the "Mark of Mastery" symbol that appears on his, Ventus's, Terra's, and Aqua's clothing.