I'm trying to remember the name of a multi-volume story. Each volume was perhaps 20-25cm x 10cm x 3cm thick, perhaps 120 pages?
- Not in colour - black/white line drawing with some cross hatch shading (not grey scale shading in the rubbed style).
- Story has a girl in a large waterproof underwater + warrior suit, like a knight but bulbous and big.
- She has some sort of "magical" abilities, I think. Not all that sure about this bit.
- She visits castles and keeps, helps people with problems, quests, etc.
- Story has a flying ship thing run by a manic-depressive (bipolar) guy who dresses like a dandy.
- This guy also has a maid/cook girl with an odd disease - she has holes and missing limbs, I think it's called "Null disease". Other people across the lands have it as well.
- Knight girl meets up with flying ship guy.
I remember the books from about 12 years ago, maybe? Not sure when they were written. I also remember them being in English AND left-top-right reading, not right-to-left style.