"I would imagine the code is read in front of the object, and it unlocks it. Part spell, part... key in the form of words."

Words have power especially ancient ones infused with magic. A bargain alone within the Underworld is enough to be binding when it is made freely. He turns toward her at the introduction, nodding in her direction.

"Lily." He repeats it after her. "You can call me Wrath."

He has no interest in creating a fake name here so he doesn't despite the oddity for mortals to call someone by the name of an emotion- a sin.