I'll point out that Susano has an attack named Rasen Kaikyo, the whirlpools that he creates under the party using the foot or so of seawater covering his arena. Also, Rasen Kaikyo is the name of a region in the Ruby Sea zone (above turtle town), and apparently it translates to "Whirling Strait", so...it probably shouldn't have been listed to the east of Kugane, since that body of water isn't a strait, and I guess it's prone to whirlpools? Just in case this is somehow helpful.