I mean, in theory, you would only be casting Huton once, during the prepull, when it doesn't even cost charges (since you can reset it with Hide). After that, your maintenance just comes in the form of Armor Crush or Hakke, which is akin to Dragoon's 2nd melee combo for upkeeping their DoT and buff (and while Blood of the Dragon became a trait, the buff from Disembowel was renamed, but remains and still must be maintained). I suspect that Huraijin's primary use will be for those times you oopsied and dropped it, or for reapplying it when you don't have the option of a Hide reset (ie. after a long transition phase or something). To be honest, the ability does feel a bit weird, as Ninja already has a pretty clean system for applying and maintaining Huton.

Realistically, though, because of the duration, and the duration refresh magnitude from Armor Crush (you only need to use it once every ~4th combo), it's not nearly as annoying to maintain as Blood of the Dragon was. It seems odd to me that you deplore the shift of some of those buffs to traits as "braindead combat" and yet then ask for the same thing to be applied to a buff that takes hardly any effort at all to maintain currently, and lasts well more than twice as long as Blood of the Dragon did (and Armor Crush adds as much duration to Huton as Blood of the Dragon's entire duration), and is getting a new dedicated button to (re)apply it without costing Ninjitsu charges.