Cards
Mana Cost is indicated by the Blue Diamond which lets the player know how much it costs to summon the card onto the field.

Attack Power is indicated by the Sword icon which determines the card’s attack power. This is affected by elemental weaknesses (weaker elements will receive more damage), and also affected by the player’s STR stat.
 

Durability is indicated by the Shield icon which determines the card’s durability.

This is affected by elemental weaknesses (weaker elements will receive more damage), and also affected by the player’s DEF stat.