Before reading this page you must remember that you do not have to choose a team according to our advice. However, if you send much weaker heroes or characters from a completely different class on the mission, they may die during the mission. Missions in this game can be hard and opponents unforgiving.
The first important element of choosing a team is the strength of the character. On the screenshot above we showed where the hero's suggested strength is and where you'll find the character's strength.
Another requirement is the hero class. Carefully look at the icon marked on the screenshot above. These classes should be selected as carefully as possible.
However, if you don't have a hero of a given class, choose a character with similar abilities, e.g. take a tank instead of a DPS, not a healer.
If you choose the team properly, you should complete the mission without any problems.