Good budget defensive B skills?

I mean, you can give him darting blow and turn him into a player phase flier, which is a role he fullfills better due to his kind of mediocre balanced defenses.

Defensive phase is better kept for fliers such as Valter, but if you really insist on it, you can give Shigure renewal or maybe QR or even lance/swordbreaker as budget options, because even with darting stance he will get doubled by ayra (unless he is hone flier buffed). It basically all comes down to darting stance, which is imho a pretty bad skill for Shigure, because it pretty much limits his potential.