The great sorcerer Merlin will face several threatening enemies, it's good that he has the help of his runic cards, after all, without them, protecting the mana of life would be impossible.
4 different card types confirmed, each with its respective elements:

Earth Wall: Creates a barrier that blocks enemies from arriving on the respective side, forcing them to climb it.
Tsunami: Conjures a powerful wave that pushes enemies within its area, moving them away from the tower.
Shockwave: beams an electrical beam that damages multiple
targets in a large area.
Fire Blast: Summons a flaming explosion that causes damage in a small area, leaving the affected area in flames, the fire goes out after a while, causing damage to beings that pass through that location.