This is how Optimus and Twilight see Thunder Streak turn into Thunderwing goes in My Little Pony Transformers Prime: Princess Twilight Sparkle.
[Twilight and Optimus find themselves in the princesses' old castle]
Twilight Sparkle: Where are we, Optimus?
Optimus Prime: It looks like Celestia and Luna's old castle.
[Thunder Streak's voice comes out of nowhere]
Thunder Streak: Not another step. [comes out of the shadows]
Twilight Sparkle: Thunder Streak.
Optimus Prime: We do not understand. What is going on? Why are you here? How? Why did Celestia and Luna disappear?
Thunder Streak: Did you really expect me to let you lower that moon of yours to make way for your sister's precious sun so my fellow unicorns could admire it while I basked in your precious moonlight?
Twilight Sparkle: Precious moonlight?
Optimus Prime: What are you talking about?
Thunder Streak: So, I will make Equestria see the true meaning of your night by making it last longer and all that deny it WILL PLUNGE INTO CHAOS!!
[Thunder Streak's front hoofs tear a hole in the balcony he's standing on. A dark shadow creeps up the wall behind him, cracking the stained glass window above. Thunder Streak raises his hooves about his head and the moon rises in front of the sun, causing an eclipse. Twilight and Optimus look on in horror as Thunder Streak is englufed by Dark Energon rising from the ground. The Dark Energon glows and it shatters to reveal Thunderwing, whose once green eyes turn red and his teeth grow sharper. Thunderwing lands on the platform and laughs evilly as lightning crackles around him]
[Optimus and Twilight gasp]
Optimus Prime: No. It can't be.
Twilight Sparkle: Thunderwing.
Thunderwing: So that's why now there can only be one powerful being in Equestria. And that powerful being is me.
[Thunderwing shoots his cannon at the wall then at the ceiling, causes rubble to fall. Optimus and Twilight quickly dodge out of the way as the rubble hits the floor. Optimus lands on his back with Twilight in his arms. They then look up to see Luna and Celestia standing above them. Luna and Celestia stare into the smoke as Thunderwing comes out of it]
Princess Celestia: Thunder Streak, we will not fight you.
Princess Luna: You must let me lower the moon. It is my duty. And your duty is to sleep through my night.
Thunderwing: Thunder Streak? I am Thunderwing. I have one duty now. To destroy the both of you! [shoots lightning at Luna and Celestia, who dodge out of the way]
[Thunderwing shoots his cannon at them and they again dodge the attack. The blast creates a hole in the roof, which Luna and Celestia fly out of]
Thunderwing: And where do you think you two are going?
[Thunderwing unfurls his wings and flies after them. Twilight and Optimus follow and after a short chase, Thunderwing finally manages to score a direct hit on the princesses]
Twilight Sparkle: Celestia!
Optimus Prime: Luna!
[Twilight and Optimus dive after them while Thunderwing laughs triumphantly]
[Twilight and Optimus land beside Celestia and Luna]
Twiight Sparkle: No. No. Why would Thunder Streak do this?
Optimus Prime: Why now?
[Twilight sobs while Optimus pats her head in comfort. Celestia and Luna get back on their hooves]
Princess Celestia: Our most youngest subject. We are sorry.
Princess Luna: But you have given us no choice but to use these.
[A platform rises. The Elements of Harmony, in their original form, are on top of it]
[Princess Celestia and Princess Luna walk towards it and so do Optimus and Twilight]
Twilight Sparkle: Are those the Elements of Harmony? But that's how they looked in... the past. This is the night you banished him.
Optimus Prime: Of course. How did we not realize?
[The Elements float off their platforms and the Element of Magic rises from the ball at the top]
[Princess Celestia and Princess Luna use the Elements to create a rainbow circle around them then fly up to face Thunderwing]
[Thunderwing sees them and fires his cannon but Princess Luna and Princess Celestia use the Elements to fire a rainbow beam at Thunderwing which he is overpowered by]
[The beam sends Thunderwing to the moon. His face appears on its surface]