He hadn't been allowed to talk to her. SHIELD had been very specific. He could only watch, and as soon as she figured out what he was doing, he would have to leave. Don't talk, don't let her know what you do. Easy as that.
So he sat, and watched. Watched the caged animal, the pacing tiger, restless and afraid. He saw her struggle to remember, and felt her pain, her rage and her fear when she finally did. He watched her as she cried, weeping tears of agony, revolted by what she'd become. He felt the heat of her burning hatred, directed at those who had turned her into this, into this monster. She hated every single human, every single Jotunn, and every single Aesir. But that emotion paled in comparison to the hatred she felt against herself.
To anyone else, Loki looked bored, indifferent, as if she couldn't care less about being captured, but he could see past all of it. He could see the memories, the pleasant ones and her dark secrets, both carefully buried away, but not safe from him.
It was painful to see, heartbreakingly so. He no longer saw the villain who had attempted to take over his planet, ending lives as if they were worthless. He saw the woman who liked to read, who spent most of her time at the library. He saw the girl who would run for her mother, proudly announcing that she had learned something, a new enchantment, or improved her shapeshifting skills.
He saw her being scolded over and over again. Though it was not forbidden, sorcery was frowned upon. A true Aesir was supposed to be a brave warrior, fearlessly defeating their enemies in combat. Lies, deception and trickery were skills reserved for weaklings, fools, cowards. Why wouldn't she attempt to be a true warrior, like Sif? Or if she didn't want to be a warrior, then be a lady, like your mother, Loki.
He saw the determined look on the young woman's face as she removed anything related to sorcery from her chambers. He saw her as she went to the training room, dressed in battle attire, and asked her brother and his friends to train her. Loki lost every single practice fight and by the end of the week she was all sore and bruised, but she didn't care. Someday she would be like them, brave warriors, and her father would be proud of her. It had taken only a year until Loki lost her patience and used a trick to finally win from Thor. He ran into the wall behind the duplicate she had created, and when he turned around he was just in time to see his sister throw her sword onto the floor and run away, silent tears running down her cheeks.
The next day she was wearing a long, elegant dress, instead of the armor. She was suspiciously quiet during breakfast, and later that day she asked Frigga to teach her how to be a lady. Frigga had hugged her, saying that she wouldn't have to change. But Loki insisted. Odin had given her two options and she had failed the first. So she learned to sew, to make small talk with other people, and to play various musical instruments.
It wasn't until she subconsciously began to enchant the needle and thread to do the boring work themselves that she realized that this wouldn't work either. The simple tasks and mundane conversations made her feel empty, and Loki just couldn't bear the thought of having to live like this for eternity. She didn't show up for lunch that day. Or for dinner. He saw her as she was hiding in a shadowed corner of the palace library, crying silent tears until she fell asleep.
It was late at night when she woke up to a hand on her shoulder. Her first reaction was to pull away, but then she saw it was Sif, and Loki completely broke down. When she was finally done rambling, crying and complaining, Sif adviced her to do what she wanted to do. Sif was born to be a lady as well, but wanted to be a warrior. She struggled to prove herself worthy, to prove that a woman could fight just as bravely as a man. And if she could do that, then why couldn't Loki prove that magic wasn't for cowards? That it was an amazing skill and would be very useful in combat?
The next day she wore one of the simple, more comfortable dresses that she had always liked to wear before her attempts to be what Odin wanted her to be. Everybody could see the difference. She no longer looked empty and miserable. And when Thor announced that he would hunt for Bilgesnipe that day, and asked her if she wanted to join him and his friends on that hunt, she agreed. Armed with only the daggers she always carried around, Loki fought like never before, cleverly using her tricks and enchantments to defeat the beasts, having the time of her life.
Her joy didn't last long though. The next memory he found was one of Odin scolding Loki once again. She dutifully listened, not objecting to anything he said. When he was done, she simply asked if there was anything else he wished to discuss, and if not, might she be excused?
That was the moment when Loki Odinsdottir became Loki, goddess of lies and mischief. I do what I want.
Charles was so concentrated on Loki's memories that he didn't notice the guards approaching until they opened the heavy doors and entered the room. They opened the cage, and surrounded the sorceress, who just shrugged and patiently waited for orders. They escorted her away, and Charles followed when his temporary partner, Stephen Strange, rose from his seat to follow. Just as Strange had passed, a few agents turned, asking him to report to the director. Director Fury was in a conference room, watching the life feed from the car they used to transport Loki. His heroes, the Avengers, were all seated along the large table, waiting for him to speak.
He briefly studied each of them. The one who intrigued him the most was Thor, the god of thunder, and brother of Loki. He was concerned about his sister, feeling responsible for what she had done, thinking it was mostly his fault. If he had treated her differently while they were younger, it might not have ended this way.
"Know your place, sister." "Silvertongue turned to lead?" "Only a coward would use trickery in combat." What had once seemed to be harmless mockery, now sounded like cruel words, directed at someone he loved, who had started to believe them. A coward, a burden, a stolen relic. It pained him to see how horribly wrong it had all gone.
This would be his only chance to attempt to help the woman. So Charles asked him to sit down, and told the young god what he had seen. He kept the memories he'd seen to himself though. He was against such unnecessary violation on someone's privacy, and thought it would be better if Loki told Thor about those when, if ever, she felt ready to do so.