If you loved Mobile Suit Gundam Thunderbolt: December Sky, try Mobile Suit Gundam: The Origin VI – Rise of the Red Comet
A bridge between a film you've already seen and one most people haven't. Here's what they share, and what the second one does that the first one doesn't.

Mobile Suit Gundam Thunderbolt: December Sky

Mobile Suit Gundam: The Origin VI – Rise of the Red Comet
What they share
Theyboth carry the foreign gem, raw mood tags, and they sit in Action / Animation / Science Fiction / War territory. If that's the register that drew you to Mobile Suit Gundam Thunderbolt: December Sky, the second film will land in a comparable space — through a different lens.
What Mobile Suit Gundam: The Origin VI – Rise of the Red Comet is
You witness the Battle of Loum, a turning point for Zeon. But their victory comes via mobile suits, and a pilot known as the Red Comet rises. Operation V begins as the Federation retaliates. Yasuhiko and Imanishi visualize a conflict where technology and charisma shift the balance of power, leaving a changed world order.