Complex sentence: Adam follows Zuriel to the Wessex Institute, where he learns that Naberius plans to recreate Frankenstein's experiment and create thousands of reanimated corpses as the souls of the descended demons will be able to return from Hell if they have soulless bodies to possess.
Split into simpler sentences: Adam follows Zuriel to the Wessex Institute, where he learns that Naberius plans to recreate Frankenstein's experiment and use thousands of reanimated corpses as hosts for souls of the descended demons. The demons will be able to return from Hell if they have soulless bodies to possess.