Alright, I made restrictions for Eris's power. It'll be pretty important to know about when she's fighting, so here it is:
Energy Usage: Consistent use of Eris's power drains a large amount of energy from her body. After using 55% of her energy, she starts to lose her ability to hear, and goes completely deaf after losing 65% of her energy. Once she's used approximately 75% of her power, she starts to see hallucinations. Her energy can also drain when she does physical activities.
Congenital Heart Disease: Eris was born with a heart defect that occasionally messes with the muscles that make up her heart. Eris doesn't know the full extent of it, but when under emotion stress, Eris's heart muscles spasm causing a sharp pain in her chest and difficulty to breathe. As her powers formed it frequently happened due to her inability to control her powers and her emotional instability. But as she's learned self control, it's gotten less frequent.