|The Classic Dragon build. Kana can run it well too. Kana can be seen as a hybrid between Nowi and his mother, Corrin(F) with more even defensive stats, good speed, but attack between the two. While access to boon/bane is usually extremely problematic for free units, Kana has a good enough spread to be fairly viable without them.
Lightning Breath+ is the weapon of choice, with the +Spd refinement or +Def refinement, depending on whether you want to try to focus on dodging doubles or just increase bulk. This lets Kana counterattack from any range, allowing him to fight off bows, which is among the more common threats that specifically needs to be countered.
Reposition is a standard, powerful movement tool that allows tanks to move units behind them, and then acting as a wall for them on the enemy phase, or just generally moving units around.
Bonfire is the special used. Kana has solid defense, and the 3, turned into 4 cooldown special works especially well, as Kana is unlikely to get doubled and thus wastes no efficiency in firing off Bonfire
Alternately, Aether can be quite strong, as Kana has fairly good attack to be able to dispatch most units oin one combat, thus having Aether up to help take out a second enemy while healing him up to a good amount of HP.
Steady Breath defines the build, allowing Kana to quickly gain special charge when baiting the enemy in. This means that he wants specials with even amounts of cooldown (or odd amount normally, as Lightning Breath+ brings it up by 1) as to not lose efficiency.
Alternately, Warding Breath is also a strong choice, increasing his res bulk instead.
Quick Riposte 3 is the second skill that defines this build, Kana, who has fairly good speed but not overwhelming amounts, to always double on return.
Alternatey, one can run other B skills such as Guard 3 or a breaker to help stop Bold Fighter nonsense or give him a better player phase with breaker.
Fortify Dragons is the skill Kana naturally comes with and is quite powerful, but other options include Panic Ploy 3, while Kana's HP isn't the highest it's enough to ploy blade mages. Alternately he can run any Hone/Spur/Drive to good effect, as well as smokes.
Close Def 3 is a strong choice for S skill, bolstering Kana's melee matchups. Alternately Distant Def 3 is also strong if you're looking to make him your archer counter.
If you run Guard 3 or a breaker as Kana's B slot, you will want Quick Riposte 3 to be your seal, allowing him to guarantee make a counter attack.