Okay so we don’t know when Ty Lee learns chi blocking and we don’t know why; what if it was the day Ozai burned Zuko?
Imagine guys, that’s her childhood friend, what if she was THERE? With Mai sitting next to her.
Imagine her seeing the sheer terror on her friend’s face as her first love is disfigured and publicity shamed by his father.
Imagine her looking over at Azula and seeing the fire reflected in her eyes and the smile on her lips. She knows how much power and hatred are inside her and she, a nonbender, is so afraid of what she could do if she set her mind to it.
And then Ty Lee makes a decision; she tells herself, bender or not, she’ll never let one of her friends be hurt like that again.