The Story of Rell
Rell was taken by Noxus as a child — identified as a ferromancer, a mage who can control metal, and brought to a military academy that turned children with magical gifts into weapons for the empire. She was trained not as a person with a gift but as a resource to be optimized, and the training included ensuring her loyalty through methods that prioritized effectiveness over anything that might produce complicated feelings about Noxus later.
What they produced was someone who learned exactly the lesson they intended — strength is what matters, weakness is unforgivable — and then applied that lesson to her own assessment of the institution. Noxus was weak. It was a system that valued people only as instruments and then discarded them when the instrument broke. She had seen the other children who came through the academy with her; she knew which ones were dead and which ones had been assigned to things that would get them killed. This is weakness. This is failure.
She broke out and turned the education against its educators. Her ferromancy now serves her goals, which involve the specific dismantling of the institutions that made her what she is. She is blunt, she is angry, and she is precise in exactly the way her training intended and for purposes her trainers did not. She has not processed everything that was done to her. She may not have the equipment to process it — they took some of that too.