- Acceptable Political Targets: Governor Charles Hamilton of Montego. On top of being a womanizer living in the lap of luxury at his people's expense, he's also a Dirty Coward who's willing to sacrifice his own men to make a speedy escape from the Flint Pirates.
- Base-Breaking Character:
- Alex. Is he a refreshing foil to his more dour and pensive older brother? Or is he an flat character who only serves to play second fiddle to Jon? His being Out of Focus for much of the story doesn't help the matter. At least until the Second Battle of Ephesus kicks in.
- Kaguya. Some consider her an interesting character with her divided loyalties to her father and the Flints being a big arc of her interactions with them, alongside her antagonistic relationship with Lorelei. Others consider her an anime stereotype with no true personality or background to set her apart.
- Ensemble Dark Horse:
- Robert Maynard all the way. Par for course given how competently he fought the U-7501, despite his Ranger and her sister ship Relentless being seriously outclassed. Needless to say, readers were relieved to see him survive to fight again.
- In spite of her minor role, Ciel is very much loved. Namely by the author's family.
- Magnificent Bastard: Admiral Raphael Drake. So much so readers regularly compare him to the great Hans Landa (if the latter had joined the Kriegsmarine instead of the SS).
- As an obvious byproduct, some readers refer to Drake as "Admiral Landa" or "the Flint Hunter".
- Mexicans Love Speedy Gonzales: As one would almost expect, Barbarossa is especially popular with Arabic/Muslim readers.
- Japanese readers are also fond of Kaguya and the Blue Dragon proper. It helps that the former is a well-rounded character that avoids most Japanese/anime cliches, and the latter is meant to evoke real world Japan as opposed to the usual Disneyfication.
YMMV / Black Sun