The rivals are two of the main characters in Pokémon Umbra. They become well-known to the protagonist throughout the course of their journey. The rivals have similar skills, goals, and achievements as the player, which oftentimes causes conflict. Rival characters appear frequently during the player's quest, usually to challenge the player to a battle. Defeating a rival may be a primary or necessary goal of said character.
A rival is a recurring opponent to the protagonist throughout the game. The rivals will be met when the player receives their starter Pokémon. They will also receive a starter, and either Damien or Eva will participate in the player's first Pokémon battle. From then on, Damien and Eva appear frequently throughout the player's journey, meeting and battling the player at various points in the game with a progressively stronger and diverse party. They usually must be defeated in order to continue through the game; the most important of these battles happens either right before or during the player's challenge to the Elite Four.
After the defeat of the Elite Four and the Pokémon Champion, the rivals can be battled at the player's leisure during certain times with increasingly powerful Pokémon.
Unlike the protagonist, the rivals do not have the option to be named by the player.