Originally Posted by
Tsukino
Except 蒼気砲 isn't read "aokijyuu," it's read "soukihou." Any actual Japanese person would know this.
Additionally, though 砲 can be read "jyuu" and mean "gun" on its own, hardly anyone ever does this. The character for that is 銃. 砲 is used almost exclusively in compound words to mean "cannon."
Not that this is important, at all, to anyone, but I'd go with "azure spirit cannon." No one in their right mind would actually directly translate martial arts kanji compound abilities though, as Brannigan already mentioned.