Every hero in Bloodline belongs to one of six elements: Earth, Thunder, Water, Fire, Light, and Dark. Each element
does 50% more damage and receives 50% less damage against one element suffering the opposite effect against another; Fire heroes, for instance, have this advantage against Earth heroes, but do 50% less damage and receive 50% more damage against Water heroes.
The two exceptions to this rule are Light and Dark heroes; both of them do increased damage to one another.
Because of this, it’s crucial to maintain and level up an array of heroes across all six elements, as certain boss fights rely heavily on having a countering element to beat.