This is how Thunderwing drains Twilight's friends of their magic and Thunderwing betrays Pythor goes in My Little Pony Transformers Prime: Optimus' Kingdom.
[Twilight's friends and the Autobots meet up]
Applejack: Alright, y'all. I think we've warned everypony to stay inside.
Fluttershy: I'm sure Pythor will catch Thunderwing and this will all be over soon.
Ratchet: You got that right.
Rainbow Dash: I'll bet he takes his sweet time.
Pythor P. Chumsworth: Or perhaps these things just take time.
Fluttershy: [gasps] You're back! Did you bring the cucumber sandwiches?
Ratchet: What the heck would we need those for?
Pythor P. Chumsworth: I did. I imagine they'll be your last decent meal for quite some time.
[He puts them in a cage]
Main cast bar Twilight and Optimus: [various exclamations]
[Thunderwing appears along with the imprison Celestia, Luna, Cadance, and Twilight]
Pythor P. Chumsworth: Ta-da!
Thunderwing: You've gathered up all of them?
Pythor P. Chumsworth: And the little dragon, too.
Fluttershy: [crying] Why are you doing this? I thought you, Twilight, and Celestia were friends!
Ratchet: What are you crying for?
Pythor P. Chumsworth: Oh, we were. But Thunderwing offered me so much more than just friendship. Surely you saw this coming.
Fluttershy: [crying] I didn't. I really didn't.
Ratchet: Sssh. There, there.
[Thunderwing chuckles darkly and drains the ponies of their magic]
Thunderwing: You really think he'd do anything for them?
Pythor P. Chumsworth: If Optimus has magic to give, it will be yours. Soon there won't be a Pegasus, Earth Pony, Unicorn, or Alicorn who will be able to stand up against us.
Thunderwing: Us? Who said anything about us?
Pythor P. Chumsworth: You did.
[Thunderwing thinks then laughs out loud]
Thunderwing: You've helped me grow strong, you've provided the means by which I can obtain Prince Optimus' magic, and now you are no longer of any use to me.
[Thunderwing picks up Pythor and drains his energy. Pythor looks up weakly as Thunderwing drops him next to the caged Autobots and ponies]
Pythor P. Chumsworth: [weakly] But you said this was a sign of your gratitude and loyalty. A gift from someone close to you.
Thunderwing: My brother who betrayed me. It is as worthless as he is.
[Thunderwing again laughs menacingly]
Applejack: Surely you saw this coming.
Bulkhead: Yeah, ya big creepy lizard.
Pythor P. Chumsworth: [weakly] I didn't. I truly didn't.
Twilight Sparkle: Now, look who's acting like Fluttershy.
Princess Celestia: Look at what you've done, Pythor! You should be ashamed!
Pythor P. Chumsworth: [weakly] I am, Celestia and Twilight. I really am.