History[edit | edit source]
House of El and House of Zod created Doomsday as a weapon during Krypton’s pre-cataclysm era. Once it became clear that Doomsday could not be controlled or destroyed the House of El and House of Zod sealed him away. The vault has the combined symbols of House of El and House of Zod and was design so that a member of each house would have to use their blood unlock the door. After the Cythonnites witnessed the destruction Doomsday wrought they decided to remain in the catacombs of Kandor and protect the vault.
When General Zod went back in time he began looking for the vault to use the weapon inside against Brainiac.