Hero groups are the best-case scenario for heroes according to their ability types. Each hero's group type is shown in the top-left corner of their upgrade screen.
Wanderers. These hero group skills are generally a good addition to any team.
Kingdom Heroes. These heroes are the best at buffing allies and weakening enemies.
Sworn Enemies. Each hero in this group is a blood enemy of a particular giant and is the only one to extract Giant Shards during battles.
Giant Slayers. These heroes' abilities weaken giants of a certain element.
Defense Heroes. These possess the abilities that are most effective for defending your castle.
Siege Heroes. These possess the abilities that best counter Defense Hero skills.