You switch Heroes in and out of your team by pressing the Hero you want to switch out in the "Edit Team" view and then either pressing the red X on the Hero to remove them from the team, or selecting another Hero from your Hero Roster to replace the Hero.

The Defense Team is used when other players raid you. These Raids typically happen when you are offline. You can assign a Defense Team in the “Edit Team” view by ensuring the “Defense Team” checkbox is ticked. The Defense Team is selected when the checkbox is ticked.

When you want to raid another player, the team you’re going to attack with is selected in the “Ready To Battle” view under your player information.

At this point, you still have an option to Edit your teams by pressing the “Edit Team” button. This will open a new view, where you can edit and view your existing teams. The Team that you wish to use in a Raid must be selected and visible in the “Ready To Battle” view when you press “Attack”.