Somehow, the subject of how they met came up. That old story. Shay recanted it with a smile, able to repeat word for word how things went, just as Theo could. That something so seemingly insignificant could prove to be so important at a later date.
It began with something as innocuous as a book. A lone book in an empty library in the middle of the night...

Shay had been seeking refuge in the library from one of the older boys. He was a teenager and while he was short for his age, and on the heavier side, he was quicker and stronger than Shay. He'd pushed her before. He'd risen his fists to her. Shay didn't like to be afraid, but she was.
The library had always been Shay's sanctuary. The books here were old and damaged. The selection wasn't as vast as the school library, but many of the kids in the orphanage here didn't come into the library. Safe. And it smelled of books and adventure.
Shay could see a dim light as she rounded one of the shelves. Her six-year-old body was ready for the possibility of some type of retribution, but what she found was more shocking. Sitting at one of the long, battered tables was a boy that seemed to be around her age.
Shay stood and gawked, too nervous to approach. She turned sharply and searched the titles of the books, trying to find something she wanted to read.
Simon really wasn't all that bad, he only reacted when Theo was feeling threatened. Right now he simply whispered things in the back of the boy's mind as he read. On this particular day he had already gotten talked to about his interactions with the other children, or lack thereof. He simply slipped off to the library after that, no one bothers you when you're reading. After some time went by he glanced up when he noticed some movement.
According to Simon she was "that one girl" that they'd apparently seen being harassed by one of the older boys. Of course neither of them liked it, but they also concluded that maybe they should keep their heads low. He saw her duck out of sight, just another person who was probably scared of him. He huffed, then took his book, and left without another word.
@Foxy
She did this the next night.
And the night after that.
Soon, she was sharing the library with that boy again, they weren't speaking to each other, but they'd shared a few books. She'd wondered off to another section in search of something new to read.
Having found it, Shay was resting back against the bookcase, sitting and reading excitedly when a shadow was cast over her person. She looked up and saw Jimmy, one of the older boys who often taunted and pushed her around.
"Gah! I knew I'd find you here," he sneered. "I kept wondering where you was always runnin' off too. The hell is that?"
He snatched the book from her and Shay stood up slowly. Jimmy was a good few heads taller and about ten years older than her. He'd never been picked up, like most of them.
She could see why. He was violent and crude, and there was this predatory look in his eye that scared her. Shay didn't know why he was always drawn to her, but she didn't want to be alone with him in a library and she'd entirely forgotten about Theo, who she wasn't even sure was still around.
Eroshay turned to run from him, but Jimmy was quicker than her. He took hold of her hair and yanked her back, getting a cry of pain from her.
"The hell are you going?"
They'd continue like this until one particular day Shay was taking longer to get back. Initially Theo wrote this off as her having run out of interesting books in the section she was in. Things were quiet until he heard a pained cry. The boy didn't really run, but he did move a bit quicker than normal. It sounded like the other girl. At Simon's urging he picked up a hardcover book on his way. Upon arriving on the scene he found the girl being yanked by her hair by an older kid. Jimmy was his name, he'd tried several times to bully Theo, each time being thwarted by Simon. Usually an arm or two would emerge from his shadow to defend him. That was about the most people would see of Simon outside of Theo speaking with him.
Theo threw the book at Jimmy's head which hit him and fell onto the floor. "Did you throw that, you little shit?" Jimmy turned to face the other boy. "You gonna say something? Huh?"
To Theo the teenager looked like a giant, part of him was ready to get thrown down the aisle or punched. He tensed, too nervous to say anything in response. Jimmy began storming over to him. Before he could say anything he felt himself being quickly lifted and shielded by several arms.
This was enough of a threat to prompt Simon to emerge from the boy's shadow, lifting him into his many monstrous arms as he did so. The cloaked creature let out something like a snarl, but closer to a hiss before shoving over the book shelves. He picked up the teen and threw him past Shay like he was some kind of rag doll. After a brief pause, the abomination set his master down and returned to the shadow. "Don't mess with us anymore," Theo spoke up, quietly.
He looked at Shay, before turning his attention back to Jimmy. "This was his fault," he said plainly as the older boy scrambled to his feet and retreated.
@Foxy
Shay was sprawled on the ground as she saw what the boy became, or whatever was part of him. Her eyes were wide; she'd never seen anything so dark or sinister looking before. It was like a monster under the bed, but this monster was here to protect her.
Jimmy was a BIG kid, to see him thrown around like that enthralled the little girl. And when he retreated -- why, Shay had never felt what she was feeling then. Was it safety? Security? Kinship?
She had never heard the boy speak before now. From that moment, Shay was mesmerized. When the owner of the orphanage ran in and threw a fit, numbly, Shay stuck to the story. Jimmy had done it. Jimmy was dangerous.
The woman, Miss Tills, was often overwhelmed and she could smell a lie from a mile away. It was a literal ability of hers. But this, technically, was not a lie.
Jimmy had done it, by messing with the wrong kids and to Shay, he had been very dangerous. But not anymore. It didn't even take a full twenty-four hours before Jimmy was shipped off to one of those orphanages for dangerous kids with uncontrolled powers.
It wasn't the end of their story with him, but that tale is for another time.
A kinship formed. An alliance.

Age 8: Wherein Theo's Habits Become Shay's
Shay lied back in her bed, unable to sleep. The night was late, so deep was it that almost no sound found her. Almost. In the distance, Shay could hear angry talking. Usually, she'd have kept away from the anger of adults, but tonight -- haunted by nightmares of death at Jimmy's hand -- Shay got up and snuck from the girl's dormitory toward the stairs to peek out and see what all the commotion was about.