While most Caster Magics provide the caster with an element to utilize (Fire, Iron, Sky, Lightning, Poison etc.), Rumble is perhaps a rare exception. Rather than utilizing an element, it is all about manipulating your magic in a never before seen style, one that is now known only to Ashuron.
The principle of Rumble is to cast the mage's magic against a solid surface, perhaps a wall or a barrier, and reflect it back at the opponent. The strength of the attack can be multiplied by reflecting it off of multiple surfaces. Likewise, the attack can pass through a magic barrier created by the caster. This can be a replacement for the reflection, aimed straight at the opponent rather than calculating all the angles.
The magic, conveniently enough, is strongly connected to the caster's current emotions. Meaning, if the caster is absolutely furious, their spells would perhaps be able to increase in strength several times. Likewise, if they were unmotivated or depressed, their attacks would not pose a threat in the slightest.
Another component of the Rumble is the enhanced sense of smell. Oddly and uniquely similar to Dragon Slayers, casters of the Rumble will possess an abnormally heightened sense of smell, being able to track down enemies from several kilometers away, as well as being able to distinguish one's usual habitat.
However, all this does not exist without a disadvantage. Many casters have been able to create an amazing comeback by utilizing their surroundings and using it to amplify their magic. However, this is not the case for Rumble Magic users. Since the Magic does not utilize an element per se, casters cannot use anything around them.The only possible exceptions being dangerously unstable structures.
Rumble Wall (とどろきしょうへき Todoroki Shouheki)- The basis of all Rumble Magic spells, if the caster cannot utilize this technique, then no other techniques would be able to work. By spreading the caster's magic outwards, a temporary wall can be made. These can act as barriers or sometimes even traps. Once a wall has been made, the caster is open to virtually limitless other options such as creating another wall by reflecting the magic off of the original wall.
When indoors, a common trick is to, rather than spreading it outwards, the caster releases their magic to the ceiling. When it comes down, the caster repeats the process, until it becomes a dense wall of magic that is constantly being reflected from the ceiling and the floor.
Rumble Airspace (とどろきくうかん Todoroki Kuukan)- The second most spell of Rumble Magic, knowledge of utilizing this is not necessarily vital however, using it's theory would allow casters to make their spells several times stronger. Similarly toRumble Wall, the caster spreads their magic outwards, the caster, rather than expelling it from their palms, release it from their entire body. The result being a large amount of force capable of shredding steel floorings.
Rumble's Infinite Reflection (轟音の無限反射 Todoroki no Muhen Eizou)- Dante uses the full extent of either his shoes or his turbines. By creating an uncountable number of walls, Dante sends a burst of magic towards one of the walls. These walls act as mirrors, reflecting the attack to other mirrors, growing stronger every time it gets reflected. It then comes to a point where the attack can become powerful enough to destroy aGuren in a single strike.
Rumble Airspace: Cube (とどろきりょうくう: りっぽうたい Todoroki Ryoukuu: Rippoutai)- A move used solely for the purpose of capture and perhaps swift elimination, Dante uses this move only when he is absolutely confident in his abilities. By using his walls, Dante creates a box like shape that traps the target within. The cube is completely airtight, and as such contains a zero airspace, or in other words, an atmosphere similar tospace. Despite the fact that it was one of the first techniques Ashuron ever made, cube has been the only successful shape, all other shapes such as spheres or pyramids being ineffective and easily destroyed.
Rumble Cannon- (とどろきたいほう Todoroki Taihou)- One of the deadliest moves in his arsenal, Ashuron charges up his magic in his leg. He kicks in the direction of the target once, releasing his magic in the shape of a bubble. Then, in mere milliseconds, he charges up his leg with magic again and kicks the bubble, sending a threatening beam of magic towards the target.
Rumble Pressure- (とどろきおさえ Todoroki Osae)- A completely defensive move that utilizes both basics of the Rumble Magic. By initially creating a "Dome" or a sealed off area with walls, the caster then releases their magic in bursts of Rumble Airspaces. Due to the vaccum like atmosphere inside the walls, the normally painful attacks become viciously dangerous, dealing a lethal amount of pain due to it becoming strengthened by the zero airspace.
Rumble Spiralaxe (とどろきねじおの Todoroki Nejiono)- A Rumble Magic move that is exclusive to Dante due to it's use of Dante's shoes. By feeding a rapid source such as a gale or fast moving water, Dante creates several walls around the turbine in his shoes in a spiral format. By releasing the energy, the blast becomes a spiral, one that, due to it's raw power and destructive shape (spiral), is more than capable of piercing the hardest metals known to man.
Rumble Platinum Wall (とどろきプラチナしょうへき Todoroki Purachina Shouheki)- Perhaps a secret art that ONLY Ashuron can cast, it is in a way, an evolution of Rumble Spiralaxe. Like Spiralaxe, Ashuron feeds a fast moving source into his turbines. However, rather than releasing it, he creates a wall with the internal energy, creating, even for a few moments, an invincible barrier that cannot be destroyed or pushed back. However, because the internal energy disappears rather quickly, the wall can only last for a few seconds.
Rumble Wiper's Lance (とどろきワイプ Todoroki Waipu no Yari)- The only Secret Art that deals with basically, in a way: nothingness. By using the concept of Rumble Cannon and kicking the air at rapid rates, the caster creates a beam like attack. However, by trapping the target in a Rumble Pressure, the attack's power becomes virtually multiplied, to the point where it can easily decimate the target, relating to the theory ofnothingness.
Rumble Opaque Hell Orb (とどろきオペークじごくきゅうたい Todoroki Opeeku Jigoku Kyuutai)- Easily the strongest Secret Art when it comes to close combat, it is also the most difficult to utilize, much less master. Originating from Infinite Reflection, the caster creates countless walls...around a single joint of their body i.e. knees, elbows, shoulders, hips etc. In addition, the walls must be placed in a way that they will create an orb like shape upon activation for maximum damage. By sending out a moderate amount of magic, the walls continously reflect the magic and create a devastating orb like attack that is so dense that the magic is actually visible.
Rumble Reversal Airspace (とどろきぎゃくてんくうかん Todoroki Gyakuten Kuukan)- A secret art created for the sole purpose of deflection, Reversal Airspace has yet to be bested when it comes to defensive measures. The caster initially creates Infinite Reflection centered solely around the bottom of his foot. They then use the concept of Cannon, kicking at the intended target multiple times in mere miliseconds. The walls, providing protection to the caster and at the same time deflecting attacks, provide to be the axis of Reversal Airspace. The strength of this secret art iis so great that it at one point deflected a mechanical structure's bullet.
Rumble Ultima Pressure (とどろきウルティマプレッシャー Todoroki Uruteima Puressha)- Obvious by it's title of Ultima, this secret art is the most destructive technique in the Rumble Magic's arsenal. By initially attempting to create the Spiralaxe, the caster, instead of releasing it in a spiral, simply releases it in a single blank. However, they can shoot it multiple times with the theory of the cannon, managing to fire off several blasts in a matter of seconds. Due to the originally destructive strength of the magic, alongside the large quantity produced, this attack is more than capable of decimating towns within mere minutes. But, Ultima Pressure is not without it's setbacks. Due to the overexertation needed to produce the kicks, the caster's legs are quite often weakened for a severely long period of time.