DragonSword: Awakening brings a host of different characters, a.k.a. heroes, for you to try out. Paying attention to your team composition will be critical.
When you are just starting out, most of the heroes will remain locked. As such, you will want to build teams with whatever characters are available. You will want to properly plan the unlocks so that you can get the best team composition. While certain heroes are overpowered compared to the rest, paying attention to team synergy is far more important.