This is how Megatron vs. Nemesis Prime goes in My Little Pony Transformers Prime: A Royal Problem.
[Optimus stands on the balcony of Canterlot castle]
Megatron: Then, I'm back. [laughs evilly]
Optimus Prime: Don't worry, Galacticus. I know how to handle Megatron.
[Suddenly, Nemesis Prime shows up]
Nemesis Prime: Yes! But can you handle... me?! [laughing evilly]
Optimus Prime: This can't be!
Nemesis Prime: If Megatronus can turn into Megatron, you can absolutely turn into me — Nemesis Prime! The better, handsomer, and more powerful version of you!
Optimus Prime: No! I'll never turn into you!
Nemesis Prime: Deep inside, you know how powerful you are. You don't need Megatronus.
Optimus Prime: That's not true! Even when we were apart, I knew I needed him!
Nemesis Prime: [laughs] Oh, please! You don't need anyone! You can do whatever you want. And all you have to do is get rid of anyone who stands in your way!
[Megatron and Nemesis Prime start fighting]
Nemesis Prime: I never should've banished you to the moon! I should've destroyed you!
[He flies at Megatron as Optimus and Galacticus duck out of the way]
Galacticus: No, you can't do that! Prime, Overlord, Bot, Con — Equestria and Cybertron need both of you!
[They duck out of the way as Megatron fires]
Galacticus: Without balance, there's no harmony!
[Nemesis pushes Megatron down but he throws him off]
[Nemesis blasts Megatron with red energy]
[Megatron fires again and Nemesis dodges]
Nemesis Prime: Who needs balance when you can have it all?! [laughes evilly]
[Megatron blasts Nemesis away]
Megatron: You can't vanquish me so easily, brother, unless you plan on smiling me to smitherens!
[Nemesis Prime is about to charge at him again when Optimus intervenes]
Optimus Prime: Enough!
[Megatron is knocked back as he jumps between them]
Nemesis Prime: [laughs] I told you I was more powerful than you!
[Megatron readies another cannon blast]
Nemesis Prime: Ugh. So much purple. We get it. You're sad. You could really use some... sun!
[He shoots a red energy beam at Megatron who encases himself in a forcefield as Optimus ducks out of the way and the beam pushes the forcefield back. Galacticus gasps as the floor piece beneath him is burned and Optimus grabs him and encases them in their own forcefield. Nemesis charges his energy as Optimus and Galacticus try to stand their ground]