FLOOR

The Exos Heroes Battle System may take a while to learn so here is a guide:  

1) Markers and Multipliers

2) Compatibility of Elements

UI Indicator for Compatibility of Elements: 

Advantage Effect of Compatibility of Elements: 

Important Note: Between the Light ↔ Dark element, the synergistic effect applied between elements are treated as Superior Elements.

Hero with Element-Type Advantage Skills: 

3) Defense and Piercing Damage

Your Defense works primarily by reducing the Enemy Skill Multipliers. For example, damage dealt by Venato (3546 ATK) and Seir (3488 ATK) versus different defense level. 

However, there is a CAP to reducing the enemy's Skill Multiplier as shown in the graph below. Hence, too high defense is not advisable. 

4) Attack Damage

The damage dealt by your Basic attack and Skill attacks are based on your final stats. 

Other Battle Mechanics will be posted in the upcoming battle guide PART 2.