Answer
Overwatch does not feature Erika because she is a character exclusive to the game Apex Legends. Erika, also known as Valkyrie, is a playable Legend in Apex Legends, a free-to-play battle royale game developed by Respawn Entertainment and published by Electronic Arts. Overwatch, on the other hand, is a team-based multiplayer first-person shooter game developed and published by Blizzard Entertainment.