"Go!" His mother had yelled at him just before she fell, before she was cut down. His father lay dead in the street, having already spent his life trying to protect Mako. He'd grabbed Mako's shoulders and his fingers dug in hard and scared and he'd taken the brunt of the heat against his back. His father caught fire. Mako saw the fear and pain in his father's face as the flames licked his body, burning through his clothes, shadowing his eyes. His father's bellowing scream roared against Mako's face until there was no more scream left in him.
He saw the light leave his father's eyes.
His mother had told him to get away, to leave and find Bolin wherever he had run off to, and told him to protect him. So Mako obeyed. He heard his mother's shrieks and looked back, knowing he shouldn't but he couldn't help it and she was there, writhing on the ground, twitching and crying and melting into death.
The firebender was smiling at Mako as he pocketed the money, and his eyes glowed.
Mako turned away and sprinted as fast as he could, searching for Bolin in the alleyways, stumbling and confused. He'd never felt so scared, never felt so lost. He tripped and fell, and as his hands reached out to catch his fall, two bursts of fire jetted from his palms.
He had to stifle a scream as he rolled on the ground, colliding with a set of trashcans. He sat up and scooted back against the wall of a building, holding himself together.
No, this wasn't happening. His parents weren't benders so he couldn't be one. Firebenders were evil and full of hate and anger and had just killed his parents and Mako didn't want that. He didn't want to bend. He wanted to be normal, he wanted to find Bolin, he wanted his parents. He just wanted his parents to wake up. He wanted to wake up because this had to be a dream.
He held a hand out and the fire arrived again, feared and unwanted.
He was a firebender.
So Mako cried.