Lucifer squeezed the angel's hand slightly, then let go. He hummed to himself as he decided on a curse to put on the dagger that was still resting against his palm.

"It's yours," he said smoothly. "I bind it to you.

Then, without warning, his other hand shot out to lie against Raphael's left wing.

"A mark," he announced. "As a reminder of our deal. I will call in the favor you owe me in time."

Under his hand, feathers darkened in an intricate pattern, Raphael's other wing mirroring the pattern even though he did not touch there. Neither did he need to. The touching part was solely intended to disconcert the angel.