Lucifer sighed at Michael's outburst. He had always been so dramatic. He watched as Michael attempted to summon his wings, and while he did they were but a pitiful picture of their former self. Lucifer tsked, shaking his head in mock sympathy (and pushing down any thoughts of actual sympathy). He reached out towards the shadow, a small sun appearing in his hand, and watched as the shadow melted away, and left nothing but a silhouette of a broken man.
"You see the truth, brother? You are but a shadow of a shadow. Glory turned dim and stuffed inside a human fleshbag. Do you know why he's abandoned you? Why he's cast you out without a word? I can tell you why. It's because he finally realizes what a disappointment you are. How you've failed him all these years. You may have cast me out of Heaven, dear brother, but you never cast me out of humanity," he hissed, egging him on.
"I whispered in their ears all the way from the bowels of hell. I caressed their hearts as I made my home within them, feeding off their forbidden desires. I delivered delicious warmth to their bodies as they committed acts of sin. I whispered in their minds, reassuring them that if it felt so good, it couldn't be bad." He chuckled, before falling dead serious. "And where, Michael, were you? Surely in our father's absence the fate of this world rested with you? His Right Hand," he spit out mockingly. "But no, you hid just like he did. You allowed the humans to corrupt themselves - for it was not just me that destroyed humanity. No, I just unlocked what was already there. But it was you who allowed me to. You could have stopped me, Michael, but you didn't. You're a failure, and you could never truly cast me out."
Lucifer had already predicted what Michael would do. After all, he'd been purposely pushing his buttons. In a flash his hand was raised, throwing Michael against the wall and gluing him there. The more he talked the more he longed for a fight. If Michael would not accept his new reality, Lucifer would force the truth upon him. Prince of Lies he may be, but he would not allow Michael to deafen his own ears. He had fallen. Perhaps not for the reasons that Lucifer's poisonous tongue spoke of, but he had still fallen nonetheless. And, despite all that had happened, once upon an eternity he had cared for Michael, had seen him as his own brother. In fact, above all, he and Michael had been the closest of the angels. But that had been eons ago, long before Man and Eden. So for now, all Lucifer could do was give him the mercy of life. After all, he reasoned to himself, Michael may prove useful in ways he hadn't thought about.
"I am stronger than you right now, Michael. I know you can tell. I am stronger, and you are weak and outnumbered. So cease this fight, and help me reclaim our home. Help me get back at He who cast you down, without even a word as to why. Join my fight, or you shall once more know my wrath."