'Thunder-Lightning dual wave'

This method emphasized on sound as the origin of thunder, its seed was an intangible sound wave that would be housed in the lungs to temper it overtime. Once it reaches the 2nd stage one would be able to produce actual thunder through a 'Lion Roar' like method, eventually using thunder as a method of summoning lightning...

However, according to science, it was actually lightning that gave birth to thunder, the only reason that such a method existed was something related to the body of the Thunder lion which is born in lightning sources, so how can humans use this method?

That was the actual point of creating 'Beast Arts', turning methods that humans are incapable of practicing into a simplified version of an elemental art, but this art was still beyond possible with normal modifications.

To make it work one would have to make it into 'Lightning-Thunder dual wave', which meant that I'd be using Lightning to produce thunder instead, conforming to the natural laws, this would also make it into an art only usable by a lightning element user with a corresponding fusion elemental art, thus almost limiting it to my use.

The greatest point of this 'Beast Art' is that it almost became a normal 'Elemental Art', leaving behind most of the side effects. The main reason for this was the existence of an already set lightning foundation making it possible for me to initiate this art.

On the other hand, normal beast art practitioners would have to transplant an organ or part of the body of the monster that they took this art from, thus leading to various side effects like beastification, lower life-span due to the pressure that part induces on the rest of the body, and even to the point going insane and confusing your origin.

Due to such effects people dreaded beast arts and wouldn't learn them unless at the last straw, as being fast to practice was somewhat the only advantage of beast arts, they would normally be considered as a last chance option.

Taking all these points into mind, I was able to finally produce 'Lightning-Thunder dual wave' as a beast art that is the closest to what an elemental art could be!

`~~`~~`

Sitting cross-legged once again, I started with the creation of the seed using my element inducing method.

Taking advantage of my thunder physique and using the lightning cell to produce a thunder like sound wave at a low volume before using my mental energy to control my windpipe to produce a sound wave with a certain frequency that enveloped the that thunder wave, finally producing a slightly tangible sound wave that could be controlled with mental energy.

Using the sound wave to achieve a full cycle of tempering through my lungs, taking a fast 20 minutes instead of the full body cell cycle, however, the progress itself was more shocking than the time it took.

[ 'Lightning-Thunder dual wave' First stage (9.7%)! ]

As if the sound wave was urging, it already started cycling on it on revolving within the lung like a bee, moreover that continued for almost 4 more hours, revolving for a total of 12 cycles in a row!

[ 'Lightning-Thunder dual wave' First stage (100%)! ]

The first stage took less than a day to complete, probably relating to being tempered by lightning already and its lower volume compared to whole body tempering, but it was still considered shocking to me!

Although I felt happy, the hard work had still to end, what came next would be the most complicated stage, 'Elemental art fusion & evolution'!