After defeating Silas agent Fowler collected the remains of Nemesis prime to show his superiors but y/n had plans for it as the autobots took it in and started to repair it, y/n and Ratchet mostly but they made a fun project out of it

After it was done y/n brought it out using a mobile control device, it was pretty simple on the outside, wireless cables connected y/n to the robot as she brought it out to show the team, the optics glowing a light green and yellowish.

She lifted her foot and watched as the robot did the same before putting the foot down as she smirked

"Haha! Success!"

"I still don't understand why we had to repair this thing, it gives me the creeps.."

"Bulkhead is right, how do we know it won't get up and walk away?" Bumblebee folded his arms

"Because it's human controlled, it's like a giant toy robot.. it doesnt even have a spark will you calm down? It's a puppet, it always has been.."

Optimus walked up to it and somewhat frowned "Please, run your plans by me. Even I was left out of your collaboration." He looked down at y/n

"It's a puppet. One that is a shocking resemblance to you.." y/n looked up at him

"So you keep saying." Bulkhead folded his arms and frowned at the dopplegangar

"This is literally a test dummy. If we ever run into a situation where it's too dangerous for a bot or human to go into we'll bring out nemesis prime. Or if we want to draw decepticon fire, from a distance they'll think it's optimus.. and if we really wanted to we could get the color scheme on this one too just to make it more real for up close combat.. it doesn't feel like you guys do, and with my martial arts skills who better to control it?"

Optimus hummed but nodded

"Relax, Optimus, it's totally safe!"

She placed the robots hand on his shoulder as optimus looked at it and frowned so she started to lightly shake his shoulder

"Come on! This is pure genius don't let it go to waste!"

Optimus softly vented "very well.. y/n, you are now in charge of my counter part."

"AWESOME!!" She fisted the air and while doing so swung at Optimus and clipped his chin as she froze and quickly disabled it "I'm so sorry, Optimus!!"

Optimus just frowned "Through training I will be your opponent, it is best you get a punch in now for it may be your only.."

She smiled a little "sweet."

A few days later they stood there in the training room as y/n stood there stretching "phew. Just don't let me hurt ya, OP." She smirked

"Do not worry for me. I will be fine."

"Alright then." She said as she stretched out her arm, extending Nemesis' servo "May the best bot win"

Optimus reached out and shook his servo before stepping back and letting his mask come out

"May the best bot win. Hand to hand combat only."

"Fair enough, it wouldn't be very wise to bring the building down on us now would it?"

Optimus nodded as she charged at him

"I prefer hand to hand anyway!"

She said as she threw a punch to his face, he unfortunately took the blow after being caught off guard but spun around after nemesis stopped behind him "Come on, Optimus!"

He charged back and rammed his fist into Nemesis' chassis, hitting it multiple times til he fell even after y/n tried to block

"Come on you big lug.." y/n pulled up her legs and arms getting him to stand again

Y/N wasn't victorious but she didn't lose either, they were at a stand still at the end and neither was winning.

She walked out of the training room with Optimus as she sighed "Well I'm getting better at getting him to stand up faster.."

"It is progress. But I will not allow it on the field until further training."

"I'm oddly fine with that. I'm gonna make some tweaks to him anyway.."

With that they went different ways.

Bumblebee and Smokescreen walked down the hall

"Ready for some sparring, Bee?? I'm so pumped!"

*Yeah, yeah but be prepared to run crying to optimus after you get your butt kicked* Bumblebee whirred cocky

"Hah! Sure, You got a deal then!"

They walked into the training room but paused "Optimus?!"

*no, nemesis.*

Their optics widen as they watched the darker version of Optimus get down. Music played in the background as they glanced around for y/N

"Y/N, what are you doing?"

She stopped and looked up as her face darkened "ahh scrap, well i was testing out Nemesis' reflexes and getting a hold of him better but then a song came on and- ugh, you caught me, alright??"

"That was hilarious!" Smokescreen grinned

*It was somewhat disturbing to see 'Optimus' dancing..* bumblebee said

"You should show the others that I'm sure they'd get a kick!" Smokescreen said

"Think so?"

"Yep!"

"Lets do it then!"

They went out to the main room after gathering the others

"Alright, What is so amazing that we all got to be here?" Arcee folded her arms

"Optimus dancing!"

They stared at him dumbfounded

"Well not optimus but nemesis prime but it's almost like watching optimus, hit it, y/n!"

Ratchet of all was mortified

Bulkhead, Arcee, Magnus and Jack just stared as Miko laughed, Raf looked uncomfortable. It was... unsettling.