Fei-Oh ("Pheo") - She's named after a rare tumor called a PHEOchromocytoma that over-secretes catecholamines like norepinephrine and epinephrine (adrenaline). The sudden release of these hormones can cause symptoms like anxiety, tremors, fast heart rates (tachycardia), sweating, and facial flushing.
(More deadly effects include: lethal arrhythmias, heart attacks, hypertensive crises.)
In Fei-Oh's case, I represented the symptoms of this hyper-adrenaline state to make her "super-humanly" fast, hyper-alert (anxious), and wearing what I consider an "exciting" costume that would certainly make me flush and sweat in person.
Side Note: 90% of these tumors are in the abdomen (adrenal glands, above kidneys). Hence, some reports say they have been "activated" by abdominal pressure. Fei-Oh activates her short burst of hyper-adrenaline by pressing her well-placed belt buckle.
Is it warm in here, or do I have a tumor?