The 72 Gundam Frames from the Calamity War that occurs 300 years prior to the events of the series were named and based on the 72 Demons of Solomon's Lesser Key. ASW-G-08 Gundam Barbatos was named after the demon of the same name, even ranking as the 8th Duke of Hell.
Each major form of the Barbatos carries an animal motif. Barbatos forms 1 through 6 were based on a ram, Barbatos Lupus on a wolf, and Barbatos Lupus Rex being called king of wolves.
This series is the first in the Gundam franchise to predominantly take place on Mars. Colonizing the planet had been mentioned before, but has not since happened until Iron-Blooded Orphans.
Of the 72 Gundam Frames, only 26 are still intact by the events of the first episode.
Gundam Vidar was the only Gundam Frame that was an exception to the demon naming rule. Though it was later revealed to be the Gundam Kimaris in disguise, Vidar was named after the Norse spirit of vengeance, as that was what the character sought after following his appearance at the start of the second season.