It's a good idea to make your highest non-Eddie character your Champion, so that your friends will be more likely to use them.
If everyone has the default Eddie as their Champion then there is not much benefit to trying out other people's characters since everyone has that Eddie.
Vary it up so your friends can try out characters they maybe don't have, or haven't leveled themselves.
- From the Cosmos, tap 'My Team'
- Select the character you wish to be your Champion
- Tap the crown icon on the right-hand side
You can change your Champion as often as you like!