(After successfully defeating Demongo and the Legion of Doom, Y/N and the other heroes reach the final floor of Aku's palace.)

Jack: This is it. Aku is on his throne. He's the last enemy standing. Are you ready?

Y/N (DOTM Optimus): More than ever.

(Then the heroes see Aku in his throne along with the fusions.)

Aku: So you got this far. I'm impressed. However, my evil will soon be law. Because you won't beat me.

Y/N (DOTM Optimus): Don't get so cocky, Aku.

(Then Y/N changes to The Last Knight Optimus Prime form.)

Y/N (TLK Optimus): I'm ready to fight you.

Jack: Okay, guys. Stay focused on the fusions.

Supergirl: Let's do this!

Robin/Bumblebee: Titans, attack!

Blossom: Let's go, girls.

(Y/N and Aku exchange glares.)

Y/N (TLK Optimus): Let 's go!

(Then Y/N uses the shield to protect himself from Aku's heat vision.)

Y/N (TLK Optimus): Time to slash you!

(Y/N tries to slash Aku, but the master of Darkness blocks his attack.)

Aku: Foolish robot hero. Your attacks won't work on me.

(Then Aku uses his hit vision again as more fusions appear.)

Steven: Man, there's a lot of them.

Superman: Don't give up, son. We can still win this battle.

Supergirl: Any bright plan?

Batgirl: Hey, we're supposed to ask this to Batman.

Batman: I have one. And it's coming here.

????: Sorry for the delay.

Finn: This voice...

Jake: Is that possible?

(Then the Battle Brawlers, Sonic and his team, KO, Enid, Red and the Heroic Hamsters come in.)

Shazam: The Battle Brawlers?

Fred: Not only that. Sonic and his team are here too.

Sonic: Yes, my team and I will help you all.

Juniper: KO, Enid and Rad too?

KO: We couldn't afford to miss this one.

Raven: And the Heroic Hamsters?

Courtney: We're here to help too.

Bumblebee: Let's keep these monsters away.

Dan: Alright, Drago. Let 's do it.

Drago: I'm with you, Dan!

(Y/N and Aku have a clash.)

Aku: Give up, fool. You will never beat me.

Y/N (TLK Optimus): I will beat you, Aku. And I'll give Cartoon Network City a bright future.

(Then a light envelops Y/N and then something comes out of a portal and attaches itself into Y/N.)

Aku: What is this?

(Then Y/N powers up before slashing most of the fusions in half.)

Marucho: Did you see that, Preyas.

Preyas: Impressive. 

Drago: Such power can make Naga look like child's play...

Aku: No... that's not possible. You're not supposed to be stronger than me!

(Then Aku shapeshifts into Nemesis Prime.)

Y/N (TLK Optimus): How weak you have become, Aku.

(Then Y/N slashes Aku's arms off as the master of Darkness yells in pain and fires a beam as Y/N dodges effortlessly.)

Y/N (TLK Optimus): It's time for you to be destroyed. 

(Then Y/N's sword glows and he prepares for the final attack.)

Y/N (TLK Optimus): This is the end, Aku!

Everyone: DO IT, Y/N!

(Then Y/N slashes Aku in half as he screams in pain.)

Aku: Nooo!!! This can't be happening!!!

(Then Aku disintegrates as Y/N returns to his normal human form and falls on his knees as Superman helps him up.)

Superman: Easy there, son.

Sonic: This fight made you exhausted, huh?

Y/N: Yes, but that was nothing I couldn't handle.

(Then the girls who got attracted to Y/N come to him and hug him.)

Girls: We love you, Y/N.

Y/N: I love you too, girls.

(The long battle against Aku has finally ended. Cartoon Network City is peaceful once again, thanks to Y/N and the heroes.)