Heroes

Hero Damage
Hero Damage is simply the amount of damage granted by your Heroes. It is raised by
 * Leveling Heroes
 * Hero DMG Talent (Max 250%)
 * Warrior Buff
 * Warrior Perk
 * Camelot
 * Round Table Mult
 * Investing Raid Souls into Heroes

Hero 2 Click
Hero 2 Click takes a percentage of your Hero Damage, and converts it into Click Damage.
 * Priest Buff
 * Priest Perk (Multiplicative)
 * Hero 2 Click Artifact (Multiplicative)
 * Hero 2 Click Talent (Max 50%)

Hero XP
Hero XP is the XP given to you when slaying Minions and Bosses of all kinds. It is used to level them up. You can start with a certain amount upon leveling the Hero Charm and boosting the Token mult, as well as the Ascension buff.