Marcus (ignoring the sounds coming from the room that Caden and Sanders are 'experimenting' in- they aren't quite inaudible, up here) goes into the room, shuts the door, sets a thirty minute timer on his phone, and his head hits a pillow.
Thirty minutes later, the timer goes off- and the whole world is dark- and he can't breath- he sits up-
And the majority of his body seems to have melted into the bed.
Okay, so he does have a power. And is apparently a good guesser thereof.
He experiments, a little, and then goes downstairs, now fully corporeal.
"So apparently I turn intangible when I go to sleep and remain so until I stop intersecting with a solid object, that's fun."