Since Nezha is a celestial Deity he doesn't know that much about the modern high tech world, he found another deity that would fit as the temporary gate guard in the celestial realm.Since you're one of his friends he asked if he can be your roommate and you agreed

Nezha was in the backyard meditating, with some Lotus petals flying around him, he seems peaceful.

You're upstairs in your room watching him

Nezha's eyes open as he stares at your window

"I know you're watching me"