If you loved Fate/Grand Order: First Order, try Fate/Grand Order: Moonlight/Lostroom
A bridge between a film you've already seen and one most people haven't. Fate/Grand Order: Moonlight/Lostroom has roughly 10.5× fewer votes than Fate/Grand Order: First Order — it's a deeper cut, not a mainstream recommendation. Here's what they share, and what the second one does that the first one doesn't.

Fate/Grand Order: First Order

Fate/Grand Order: Moonlight/Lostroom
What they share
Both films are directed by Hitoshi Nanba, and they sit in Action / Animation / Fantasy territory. If that's the register that drew you to Fate/Grand Order: First Order, the second film will land in a comparable space — through a different lens.
What Fate/Grand Order: Moonlight/Lostroom is
You walk into a room that shows you what time will take. Sunbeams cutting through full moonlight reveal a dream slipping into history. The facility’s AI has one last trick up its sleeve right before it collapses. Staffers discover the chamber wasn’t built to store memories—it was built to erase them. The designers left no manual for a place that was meant to be forgotten.