This is how Thunderwing tricks Pythor into joining him goes in My Little Pony Transformers Prime: Optimus' Kingdom.
[Thunderwing drains a Unicorn's magic into his core and the Unicorn's eyes lose their color and its cutie mark fades. Thunderwing suddenly sees Pythor]
Pythor P. Chumsworth: Thunderwing, I presume?
[Thunderwing is confused]
Thunderwing: Pythor. You're free?
Pythor P. Chumsworth: As a bird.
Thunderwing: I commend you on your escape.
Pythor P. Chumsworth: I'm afraid the feeling isn't mutual.
[Pythor snaps his fingers and chains appear on Thunderwing's wrist. Thunderwing tries to blast Pythor, but he can't]
Thunderwing: Oh, I should have known you would want to have Equestria all to yourself.
Pythor P. Chumsworth: Oh, I'm not doing this for me. I'm doing it for my friends. [hushed] Just between the two of us, it's mostly for Princess Celestia and Twilight. [squee]
Thunderwing: Princess Celestia and Twilight? You're not saying you're friends with ponies?
Pythor P. Chumsworth: Surprise!
Thunderwing: I am surprised that someone with your intellect does not see this 'friendship' is but a new form of imprisonment. Clearly you've had to abandon your true nature to stay in their good graces.
[Pythor looks offended]
Pythor P. Chumsworth: I have done nothing of the sort!
Thunderwing: Oh, please, I've seen this before. But he was always weak minded. You are Pythor, you are legend, you cannot fall into the same trap that claimed my brother! Help me to grow strong, and be rewarded with something far greater than friendship. Freedom.
Thunderwing: Once I've stripped these ponies of their magic, nothing would give me greater pleasure than to see their world turned upside down. Who better to do so than the Anacondrai leader himself? Join me, Pythor, and reclaim your greatness. Unless, of course, 'pony errand boy' is the role you've always wanted to play in this world.
[Pythor looks at the frame of the medallion and grins]