Playing arena cube -

My opponent had gained control of my batterskull. The batterskull was not equipped to anything, it was just idle. I casted a flickerwisp and targeted my batterskull that was controlled by my opponent. The batterskull blinked out of play from the flickerwisp's ability, but it never came back into play under its owners control. It went to my opponents exile, then to my exile, then it stayed in exile and never re-entered the battlefield.