- You do realize that, because you put "(NO ONE else can call him these)" and that comment down at the Bingo Book rating in there, Kai's gonna get called by those whenever someone can do so after they find out the nicknames and that Kai only accepts the nicknames being used by specific people? Can't beat up or kill teammates after all.
- Is the codename "Blank" because they haven't been assigned one yet, or are you saying the codename is actually "Blank"? I can kinda see the first in the case of a rookie ANBU (have to earn your animal mask or something). The latter doesn't quite fit in with the known theme for Konoha ANBU. Anyone else got an opinion on that?
- The Chakra Armor sounds like a mix of Raikage's Raiton Armor and the chakra armor from movie 1. Not too much issue there. Maybe you could provide a general range for how long the armor lasts?
- Chakra Threads - these the same as chakra strings, yes? You might want to switch to that because there's an anime-only attack called "Chakra Threads" that might be confused with this move.
- Chakra Enhancement - This sounds quite similar to opening the Gates while avoiding the actual use of Gates. Dunno about it. Anyone else?
- Chakra Stealth - I'm not entirely sure how you can reduce chakra signature by putting a field of chakra around you. Then again, this IS a universe where you can summon house-sized sentient animals that speak English/Japanese. Probably okay, because it can be treated as having Mesai Gakure no Jutsu and chakra suppression as a basis. An issue though is that the field absorbs stimuli, which means that it would likely absorb light - either reflected off the body or passing through the field. That could result in a "black hole" appearance to the field, which could be counter to the stealth aspect depending on time of day? If so, you might just drop the visual aspect and go with just scent/sound/chakra suppression there.
- Age - Go ahead and list current age above the break down of age when the character became a rank, because someone looking through won't know the person is a rookie ANBU and to take the age listed next to ANBU.
... Man, I need to start working on something so I don't have the time to carefully read over and consider every little bit of a new person's character sheet.