Kumo Kumo no Mi/Vayu Caste Techniques

Vayu Caste is a technique first seen in Hiro's battle against Aeolus. According to Hiro, he developed this form on during his training with Fabricio el Tigre.

Overview
Hiro wished to create a form that could boost all of his physical abilities at once, instead of just one or two. To activate this technique, Hiro combines the colder air in the mesosphere with the warmer air nearer to the ground by using some for, of cloud, usually a funnel cloud, connected from himself to the mesosphere, absorbing the air with his cloud body. This creates a powerful temperature fluctuation within his own body, thus turning him into a walking tornado.

Hiro's appearance is altered when using this technique, with his over all muscular structure increasing beyond its usual slim and lean appearance, to one that now truly demonstrates his muscular structure, given his muscles have now become more prominent. His facial appearance becomes "feral", as noted by others, given that his eyes have widened, with his pupils having gotten smaller, with a permanent furrow of the brow, even when expressing happiness. Along with these things, he hair goes from its usual neat and flat style, to a spiked up and pointy style, save for a single bang which hangs down in his face.

While Hiro is in the "Vayu Caste" state, his physical attributes, such as strength, speed, and defense are exponentially increased to a degree where he is able to overwhelm the likes of Aeolus, one who is generally immune to the likes of Hiro's Devil Fruit. Before during their fight, Aeolus had commented on the strengths of each form, yet their weaknesses, such as Indra Caste's speed, yet lack of power, and Mangala Caste's destructive power, yet lack of speed, this making both forms innefective against his foe. With that, Hiro demonstrates the destructive power of Vayu Caste.

When utilizing this technique, Hiro is able to produce powerful gusts of wind which can rival, and even surpass the power of a tornado. Using this, he can greatly amplify his own attacks by hitting someone, and releasing the powerful gale, or even use the gale to move quicker, allowing him to move in on enemies quicker. Not only this, but his normal physical attacks and speed have increased as well. Though slower, and not as powerful as his two other forms separately, this form allows him to use both of their individual strengths at once.

Though powerful, this form comes with it's weaknesses like the rest. The first weakness is the time it takes for Hiro to activate this caste, given the process it takes. The second, being that Hiro cannot simply use this form carelessly, as he cannot fully control the wind once released, and due to the pure destructive power of each gale, he could potentially danger an ally, or an innocent civilian. The third, is that this form works somewhat like a "car" if you will. As long as Hiro has fuel (aka the air inside of him), he can continue to use the form. However, when using wind based attacks, he gradually uses up this fuel, and as such gets closer to burning the form out. The fourth, and final weakness of this form is that it puts a huge strain on Hiro's body, having to contain a powerful wind inside of him, which also works like an adrenaline rush, which energizes him greatly, only for him to gradually get more tired over time. Almost every time after use, Hiro has either vomited blood, or fainted.

Techniques Utilized

 * Kyōfū Ōtsuchi (強風大槌): After coating his fist in, Hiro then punches his opponent at a high speed. Before he punches the foe away, he releases a large blast of wind along with his punch, sending the now battered foe flying for quite a ways.
 * Kyōfū Tsume no Doraiba (強風爪のドライバ): Hiro coats his arm in Busoshoku Haki, and rapidly coils his arm while compressing it at the same time. He then punches at his foe, un-coiling his arm at a high speed, while releasing a powerful gale along with it, striking his foe with a powerful attack.