Even though Klea managed to keep up against her opponent in close combat, in truth she was barely able to stand due to the continuous use of spells in this battle. Her spirit energy was running out, and she won't be able to cast spells soon, leaving her open to the other girl's attacks.
Within a short span of time, Klea was forced to use multiple tier 3 spells and her newly learned tier 4 spells. The rapid use took its toll on her, considering water spells were the hardest spells for her to master.
In addition, the opponent she is currently facing is far too slimy. Everything she tried to attack her ended up being dodged and left no effect on her at all.
When the snake girl took out her sword to fight in close combat, Klea was secretly relieved. This was the perfect opportunity to switch to using battle arts for a while and let her spirit energy charge up in the meantime.