Jinnai in canon was one of those "Human Homunculi", also known as "it's 15 pages of manga per week deadline and complex organic designs are haaaard, let's just draw simple anime dudes with even simpler weapons". XD And now he's a big lizard. XD A Lace Monitor Homunculus to be precise. Technically a flying lizard but that's no special power... he just happens to be a test flight pilot. I mean, otherwise him just wearing a dang old-fashioned fashionable flight suit thing makes less sense. And ye, I incorporated the design of his canonical Buso Renkin whip thingie into the design of his tail!
Here I've gotten around to drawing him a bit in his crazy old-fashioned and yet totally fashionable flight suit thing, hold some of his test pilot's helm (minus air mask because that's hella hard to set up on the fly). Also, him not in a flight suit and just pretending to be a Regular Human Person fixated on Cell Phone. X3 I also draw his hair the way it shows up in the manga, with it heavily implying he's dark-haired and not blonde like the anime randomly made him... um. Enh.