After the whole... hellish event with Vox, everyone was rushing to stay in the Hazbin Hotel. All rooms taken up, they were remodeling to add more rooms.

Everyone wanted to be redeemed. Voxtec was under scrutiny.

Best of all...

Alastor was free of all deals. Broken free from Rosie's leash and Vox's simple, dumb games. He found interest in something new... Lucifer. A new muse.

So when he saw Charlie was stressing herself with her dad and how tired and out of it he seemed from getting so much energy/angelic power sucked out of him. Alastor volunteered to keep an eye on the feathery king of hell.