He is first mentioned by the Creature Guide, and said to be the most powerful of all Gods.
After passing on the secret of the creeds to the player, the Creature Guide is killed by Nemesis who then proceeds to destroy the player's starting village with a Storm Miracle, forcing him/her to escape through a vortex.
Nemesis returns later on Land 2. Angered at Lethys' failures to contain the player's progress, he uses the power of three creeds to destroy Khazar and kill his creature. With Khazar's creature dead, Nemesis orders Lethys to collect the piece of the creed from the body.
Nemesis curses the player's creature as soon as the player arrives on his realm. The player is able to reverse the curse later though. After taking all but one of Nemesis villages, he uses his power to create several mega-blast miracles at specific spots of the map. After the player takes his final village, Nemesis morphs his own creature to match the player's creature (except for its alignment which is the opposite and the miracles it knows) for a final battle between the two. When his creature is defeated, Nemesis refuses to concede defeat and flees to his temple. The player then must use the combined power of three creeds to vanquish Nemesis once and for all, becoming the one true God.
- When Nemesis opens the vortex to his realm, he claims that he and the player character are the only gods remaining, even if the player spares Lethys on Land 3. This, adding to the fact that Lethys failed him, could lead one to believe that Nemesis destroyed Lethys himself before inviting the player to final conflict.
- Nemesis could be an Aztec god, judging by the Aztec village being his "main" one on Land 5, and by the fact that he is destructive and war-prone (mirroring what Aztecs are in Black & White 2).
- It could be that the Aztec god in Black & White 2: Battle Of The Gods is Nemesis, resurected by the prayer of a human, and that his actions are a form of revenge against the world for the destruction and dissolution of his power and consciousness enacted upon him by the Player Character