He might!

Aslla Piscu is meant to be a rather strong demon, but not so strong that it's odd. He'd be considered powerful, but it would make sense that he included 'also i use your shadow as my transport' as part of things

Also, he'll probably figure that Aslla would be quicker to straight up inhabit this 'jack' person than bring him back, but since Carly's vague enough that he could well be dead, more than likely the assumption will just be 'shadow demon on a joy ride but i guess carly is happy???'