Lucifer's willing to rage war on all mankind, the Demon World, and even Heaven itself to find this girl. We need to find her first and figure out what makes her so much of an asset to him.
*tired and stressed* For all we know, his bride is dead. Couldn't the guy have given us a photo or something of her?
*yelling* Yusuke Urameshi! I don't care what excuse you have this time, but you need to come back to being a detective! The world needs you again!
*thoughtful* Whether or not she's an actual heiress, this bride is obviously someone Lucifer brought into power. If its possible that we can find her first...I wonder if she'd be opposed to a contract or treaty with us.