Momo had the grace to look a bit sheepish as Signum reminded her that she didn't understand the world of the shinigami. "Sorry about that," she said. "I'll try to explain it without using the shinigami terms for things."

She took a sip of water before settling herself in to explain. "A soul is a lot like the human body, some are simply stronger than others due to variables not directly controlled by the soul itself. Just like you have a human athlete that is a natural that doesn't require a lot of training to be good, in Soul Society there are souls that naturally have a high level of spiritual energy - what we call reiatsu."

The shinigami put a hand to her chest. "This is what I am. And just like that kind of human athlete, I become even elevate my level through hard work."

"But that is only part of it," she said, pausing to take another sip of water. "In many ways, the soul is like the human mind. Some people are just born with amazing intelligence. Every once in a while a child genius is born. Such a child has a vast intellect that is already elevated well above the average person, and as they grow and learn, they learn at a phenomenal rate, quickly surpassing everyone around them, including adults."

"The same is true in Soul Society. Hitsugaya was a child prodigy, a spiritual genius per se. His reiatsu levels were extremely high and as he grew, they grew faster than his control did. He was a veritable powder-keg and when he got emotional, he lost the little control he did have. The results weren't... pretty. So everyone was scared of him, afraid to be around him in case he lost control."

She sighed. "Everyone... except me."