It's convenient that Michael is surrounded by sand because that's exactly what Lucifer needs in this moment, metaphorical or not. Just stick his head right in the sand and ignore the fact that outside the Horizon the sky is beginning to crack and maybe here he can ignore it just a bit longer.

Enough people have tried to get him to wake up and come back to reality, but he's not giving in. He refuses. Why should he come back? Back to weakness, to problems? To his gilded cage?

No. No, no, no. He's staying right here!

He's not sure why Michael seems to be playing with sand, but Lucifer isn't paying him all that much attention when he comes across him, his true form mostly remaining strong, but there are cracks here, too. Some push back, slipping towards the age-worn visage of Nick, reminding him that he was never great at forcing his will over the Horizon, but no, never again. He knows who he is. He knows what he is. He's accepted that.

This damned place can't change that no matter how much it tries to break down around them.

"This is nonsense," he says in Michael's general direction, just to announce his presence. "If you're trying to build a sand castle, you're not doing a very good job."