"Burning Deadfall" is completely stunning. While flawed, its greatness outshines the flaws with a brilliance similar to Guy's tooth-ping.
Characterization wise, Kisame is definitely the best done, despite the story being from Iruka's POV. Kisame is bloodthirsty and ruthless, but also has a sense of humor and is extremely engaging to speak to. He holds your attention not for being blue, but for being incredibly dangerous and somehow friendly at the same time. Iruka comes across as much colder than he does in canon, and while it is true that the setting makes this almost necessary, it is difficult to see Iruka's old warmth shine through during bits with Naruto and the Epilogue Scene. Itachi is difficult to characterize in general, so that's fine, but Kakashi is much more serious than expected, lacking a lot of his usual dry wit.
Action is one of this fic's strongest aspects, however. Kicks, punches, ninjutsu, gore; all are expressed to near perfection in just enough detail to be engaging without going to far and causing Nightmare Fuel
or getting boring. Any fight is excellent, the climactic battle especially so. Really, there isn't anything more to say that won't completely ruin the story.
Greatest, however, is the sheer ability of the author to draw you in, however. The setting, and the way the characters interact with it, is incredible. The way the trees, in all their dead glory, are ever present, how the air feels against your skin, the burn of the Kyuubi's chakra, all this is conveyed with the vivid brilliance 1080P vido while being as subtly excellent as the Mona Lisa's smile. The way chakra flows, the way blood dribbles from wounds, and the way humans shatter under excessive strain are all treated like blown glass: delicate but profoundly beautiful.
In summary, this fic is too awesome to be missed. It grabs you by the lapels with a fury reminiscent of a wild beast, but then lays its lips upon yours with a delicacy and passion seen and felt only in the most heartfelt embraces of two lovers. Passing over "Burning Deadfall" would be a folly so massive in scope that not even the most massive conceptions of the scale of the universe could encompass it.