When the trio of heroes Daredevil, Iron Fist and Luke Cage interfered with the operations of rising crime lord Diamondback, they were dealt heavy blows in return. As they were looking for leads on Diamondback together with Luke's wife Jessica Jones, Daredevil noticed it could help people know that they actively worked together. They continued operating as a team to investigate Diamondback, and eventually became known as the Defenders - a team name originally used by aa "non-team" formed by Doctor Strange and consisting of Hulk, Namor, and the Silver Surfer, and reused by various superheroes and groups.
Further Reading Marvel Wiki
In Game Members[]
 Daredevil |
 Daredevil |
 Hellcat |
 Iron Fist |
 Iron Fist |
 Jessica Jones |
 Luke Cage |
 Luke Cage |