This is how Epilogue: Unicron creates Thunderwing goes in My Little Pony Transformers Prime: Equestria Girls.
[Unicron stares at a dark shape. He picks up a shard and infuses Dark Energon with it and throws it and Thunderwing's red optics open and he looks around and sees Unicron standing before him]
Unicron: Thunderwing, can you hear me?
Thunderwing: Yes, master. Where is Twilight? Is she strong? Is she special?
Unicron: It seems that she has learned the magic of friendship.
Thunderwing: The magic of friendship? It is the very center of the Equines' power. It was their only source of strength. I felt it!
[Thunderwings gets in a rage and Dark Energon spikes appear in the room and Thunderwing breaks free from his restraints and walks over to Unicron and bows as Unicron watches in amazement]
Thunderwing: All hail Unicron!