Although Remey was angry, she had not chosen the water and fire knuckles for no reason. She knew that they had adverse reactions when they were used together and that was her goal. If she always relied on her strength then she would one day find herself against an opponent stronger than her. She would end up beaten down without any tricks.
After having Trish teach her more about battle potions she had managed to learn about the elemental manas within the potions they were making. A lot of this knowledge had come from the experiments revolving around elemental affinity potions. Trish, the old master alchemist, and Remey needed to be very careful with the ingredients they used. If they did not follow the elemental affinity for all the herbs for a certain potion then it would fail or even explode. That was one reason that Trish had so many battle potions to defend herself.