This is how Thunderwing reveals his plan to the Mean 6 goes in The Mean 6's Return.
Mean Twilight Sparkle: So let me get this straight, Herald of Unicron. You brought us back to life just so you could destroy two of the most powerful artifacts in Equestria's history?
Thunderwing: [chuckles] You are half right, my new brethren.
[He projects an image of the Matrix of Leadership, the Element of Magic, and Cybertron]
Thunderwing: The Matrix of Leadership and Element of Magic are the only things on Cybertron and this world that can defeat evil such as Unicron and myself.
[He then shows an image of Optimus Prime and Princess Twilight Sparkle]
Thunderwing: These two meddlesome heroes have beaten me many times with them.
Mean Pinkie Pie: So? What does any of that have to do with us?
Thunderwing: My master, Unicron, sent me to destroy these objects. But they made me fail. I now know better than to do it alone. That is why I need back up.
Mean Fluttershy: So you're asking us to help? [scoffs]
Mean Twilight Sparkle: You'll need more than just us to make that dream to come true.
Thunderwing: But I won't treat you like Chrysalis did.
[The Mean 6 look confused]
Mean Twilight Sparkle: How so?
Thunderwing: Here's the deal, ladies. Help me fulfill my destiny and I will give you the power to retrieve the Elements of Harmony without the Tree of Harmony sensing your evil and returning you to your tree bark forms, thus giving you the power to overthrow any one who stands in your way and I will make you queens of Equestria.
[The Mean 6 look at each other, knowing Thunderwing sticks true to his word]
Mean Twilight Sparkle: Deal.
[She and Thunderwing shake hands and hooves]