Every enemy has a small circle of a certain color near their lifebar. The color of the circle indicates what type of Rune the enemy is vulnerable to.
The pattern in the top-left corner of the game screen will help you plan your actions and control enemies more efficiently:
⦁ Fire deals more damage to Nature (the opposite attack will deal less damage)
⦁ Nature deals more damage to Ice (the opposite attack will deal less damage)
⦁ Ice deals more damage to Fire (the opposite attack will deal less damage)
⦁ Light and Darkness deal more damage to each other, but are weak against their own Element.
The circle is also helpful in another way: it has a number that indicates how many turns before the opponent attacks. If you see a sword next to a number, be aware that the next turn might be painful!
Note! that you may encounter smarter enemies that move around and use obstacles as cover, so you may need to destroy those obstacles before you can attack the enemy. You can check your enemies' description and stats by tapping enemy's icon in the mission's lobby or holding your finger on an enemy on the battlefield.