Concept: Thief of Void in a session plagued by mystery and secret keeping between allies. Thief suffers from a lack of Void internally and cannot naturally escape having their secrets revealed, has sensory overload from never being left alone. Uses their powers to steal all Void from their friends and session, suddenly they're just plain missing. In their wake they leave once estranged allies with a sudden need to band together/cooperate more than ever before to find the Thief of Void. Thoughts?

Sounds awfully specific, but plausible.