A saiyan in Equestria?

Having reached a small, but very important milestone with "redeeming" Ato, they sat in the library to discuss their progress.

"So, Twilight should we try bringing him to Ponyville yet? I think he's ready!" said Dash excitedly

"Let's introduce him to Celestia first, she'll know what to do." said Twilight wisely

Having seen Ato seven times already, Dash and Twilight were no longer hesitant to approach him.

"Hey you, alien guy!" said Dash

"What."

"Aren't you lonely up here? These mountains sure are uncomfortable." asked Dash

"I don't mind" Ato lied

"Think about it, you could have a home, food, and you could fight for Equestria!" said Dash trying to persuade him

This caught Ato's attention, he could start over, a new life, one where he didn't have to see all of his loved ones die.

"There's only one catch." said Twilight

"You have to meet our ruler first."

Ato thought deeply for a moment and then replied "Fine, I'll give it a shot."

"Great! We can start now! said Dash joyfully

On the way to Canterlot, Rainbow Dash still had much to learn about the stranger from another planet "So alien guy, got a name?"

"Ato." he replied

"Like Tom-ato?" Dash joked

"Nope. Just Ato."

Eventually they reached Castle Canterlot, and Rainbow Dash instructed Ato to stay outside while Twilight and RD discussed their new intergalactic guest with Celestia, Ato waited outside for about a half hour until Twilight got a clear response back.

"Ato, when you come in, just follow my lead, things aren't exactly looking bright for you." said Twilight

"Typical." Ato said cynically

Ato walked into the large grand hallway with Rainbow Dash and Twilight Sparkle at his side.

"Bow to her." whispered Twilight

Ato got on his knees and without a word he bowed to Celestia, bowing to his superiors wasn't a new concept for him.

"Hey dirtbag, you disgust me, the kind who don't take responsibility for their actions, get out of my kingdom. Now." and this was all coming from the good princess Celestia

Twilight and RD were both shocked at this sudden harsh treatment coming from their mentor.

"......   I apologize." said Ato

"Don't worry, I was just testing your temper, you're free to go, new citizen." said Celestia

"What? That's it? No trials or friendship lessons?" asked Twilight caught off guard

"Nope, that's it, I was just making sure he wasn't terribly violent." said Celestia reassuringly

"Well then, what are we waiting for, let's get outta here and introduce you to everybody in Ponyville! I know people who can spread things quickly." said Dash