Complex sentence: The same edition of "Dungeons & Dragons" that introduced Bahamut also introduced his antithesis, named Tiamat, the Chromatic Dragon and Queen of Evil Dragons, as well as the mother and deity of all evil dragons.
Split into simpler sentences: The same edition of "Dungeons & Dragons" that introduced Bahamut also introduced his antithesis. This opposite was named Tiamat, the Chromatic Dragon and Queen of Evil Dragons, as well as the mother and deity of all evil dragons.