Each hero has two important parameters (besides their roles) you should pay attention to. They are main hero stat and fight line.
Fight line - Your hero can attack enemies from front, middle or back lines. You will find the information about the hero's fight line in the Stats tab of the Hero window.
It determines heroes' survival rate and what abilities enemies use against them.
Main hero stat influences the damage dealt with auto attacks. Each point of main stat adds +1 damage from physical attacks and grants bonuses to additional stats.
Additional stats - Each point of additional stats grants the following bonuses:
Strength: +40 health points (HP)
Intelligence: +3 to magic attack, +1 to magic defense
Agility: +2 to physical attack, +1 to armor