The mermaid loses her mind as one tide after another was summoned. She looks like a raging Goddess of the sea
If they are in an ocean or other large bodies of water, Eriel might have won against Rhash
Too bad that they are not in any place like that
Despite the large tides of water, Rhash was still not defeated. Since the water is in the ground he decided that he would fly
His board soared into the air and the tides crashed on the empty devastated land. Even then, the water from the flood still chased him
At normal times, Rhash would have a harder time defeating Eriel. Unfortunately for her, she let her anger take over her mind
Eriel didn't care about energy expenditure at all. She continuously summoned large bodies of water to suit her needs
This forces her mana to be drained faster than it should have been