Complex sentence: According to Diabolico Aquafiend was the only demon monster that was not affected by water like the other demons were, in fact Aquafiend lived in the waters of a lagoon near Mariner Bay.
Split into simpler sentences: According to Diabolico, Aquafiend was the only demon monster that was not affected by water like the other demons were. In fact, Aquafiend lived in the waters of a lagoon near Mariner Bay.