This is how Megabug rises goes in Antibug (CTaRAoMToLaCN).
[Sci-Ryan finds Megatron all sad and alone]
Sci-Ryan: Galvatron? Why are you sad?
Megatron: Chloe is akumatized, Sci-Ryan.
Sci-Ryan: Well. We can try to turn Chloe back to normal for Sabrina. Besides, you should listen to Starscream when he said that you.. [mimics Starscream] Reunite all Decepticons and crush all who oppose you under your mighty heal.
Sci-Ryan: But, you should trust Ladyan. And I think Bertram is Sunset's bodyguard.
Megatron: Ladyan ruined my chance at being a hero, Human Ryan! And I don't trust him. If I were you, I would not show up like Vanisher.
[Megatron runs off]
Sci-Ryan: Wait! Come back!
[but, he's gone]
Sci-Ryan: I think he got anger issues. Maybe I should tell Sunset that her ex-bodyguard has flown off to a nice big beach. With a nice big drink. And a woman with nice big... Bags of ice for his head.
[Sci-Ryan sets off to find Sunset. Meanwhile, at Hawk Moth's lair]
Ryan Repulsa: Partner. I think this Con Leader have some anger issues and gained his interest in inflection oppression.
Hawk Moth: You can send an Akuma to power this robot up, partner.
[Ryan Repulsa fills the Akuma with dark energy]
Ryan Repulsa: Fly away, my Akuma. And Akumatize the former Con Leader!
[The akuma flys out the window. Meanwhile, Sci-Ryan tells Sunset about Megatron]
Sci-Ryan: And now, Megatron has run off to who-knows-where or joined the Decepticons again.
Sunset Shimmer: Is that a joke?
Sci-Ryan: Yup. I think he regained his interest for inflicting oppression. And forget about you.
Sunset Shimmer: What?!
Sci-Ryan: Take a peek.
[Sci-Ryan pulls out his phone and plays a video]
Sunset Shimmer: [in video] Take my hand, Megatron. Let me show you about friendship.
Megatron: [on screen] No, Sunset. I am a villain and I always will be. Demon girl.
[Sci-Ryan stops the video]
Sci-Ryan: In conclusion, I think Starscream should forget about him.
Sunset Shimmer: But, we won't. We got to find him.
[The Akuma flies over Megatron and lands on his Ladyan bracelet and a butterfly frame appears around his eyes]
Ryan Repulsa: Megabug. I am Ryan Repulsa. I heard that Ladyan let you down as a hero. I want his downfall as well. So, shall we take him down together? If so, I give you the powers of Antibug. And in return, you need to do me and Hawk Moth a favour.
Megatron: You can count me in, Ryan Repulsa. There will only be one hero in Paris.
[Megatron lets the Akuma consume him and he becomes Megabug]
Megabug: Me! Megabug!
[He looks on a TV screen on his yo-yo]
Ladyan: [on-screen] Kitty Noir and I are an unstoppable team. Including SwanSong and Flutterwing.
Megabug: Mwah! Your time is up, Ladyan.
[Bertram sees Megabug]
Bertram T. Monkey: Galvatron? I didn't know you are doing cosplay.
Megabug: That's Megabug to you!