Complex sentence: Then they fix and clean up the mess the Black SoShi left, suddenly, Seohyun taps the computer monitor lightly and accidentally opens the portal of the parallel universe again causing the door to be opened for a possible return of the Black SoShi.
Split into simpler sentences: Then they fix and clean up the mess the Black SoShi left. Suddenly, Seohyun taps the computer monitor lightly and accidentally opens the portal of the parallel universe again causing the door to be opened for a possible return of the Black SoShi.