I second muscatlove! This is by far the most impressive Rikkai fic I've read thus far; your grasp of the characters is simply amazing - especially Yukimura and Yagyuu, as others have pointed out, and Akaya and Sanada are dead on as well.

I love how you've captured that thing that lots of other fics ignore; that behind Rikkai's crack and teenage boy showmanship is something fierce and deadly.