This is how Quintesson revives Optimus and Twilight goes in The Return of Optimus Prime and Twilight Sparkle Part 1.
Quintesson: Once again, we are ready. But if this doesn't work, Optimus Prime and Princess Twilight Sparkle shall never live again.
[They push a button and a flash of light happens. However, Optimus and Twilight don't move]
[Lightning bolts flash. Pyrotechnics abound. Even Sky Lynx is in awe. Optimus and Twilight's bodies shimmer with light. The intensity increases. The machine whine grows louder. The light fills the screen, forcing Sky Lynx, Celestia, and Luna to turn and cover their eyes. Everything goes white. Then, in the whiteness, we see the forms of Optimus Prime and Twilight Sparkle rise. We only see them in silhouette because of the intensity of the light. Sky Lynx, Celestia, and Luna force themselves to stare into the fiery glow. There is an explosion of light, and then all color returns and we see the very powerful Optimus Prime and Twilight Sparkle standing full and proud]
Sky Lynx: Optimus.
Princess Celestia: Twilight.
Princess Luna: You are alive.
Quintesson: I've done it! Optimus Prime and Princess Twilight Sparkle live again!
Sky Lynx: It's true. Our leaders are back.
Princess Celestia: Welcome back, you two.
Princess Luna: We must act quickly.
Optimus Prime: Yes, Sky Lynx and Your Hignesses. And this time no force in the universe can stop us.
Twilight Sparkle: I'm with you on that one, Optimus.
[To be continued...]