Daoist Chu and Ziran's conversation shifted from the Outer Territories and Farlands to other matters which didn't interest Lin Mu as much, so he fully focused on his cultivation.

He had grown five of the basal elemental cores to the Immortal level and was now stumped with the Wind and Lightning cores.

'I do have a few herbs for the Wind Element, but for Lightning element I barely have a handful.' Lin Mu thought to himself.

He had hundreds of Wind Elemental Spirit herbs and about ten for Wind Elemental Immortal herbs, but he only had six Lightning Elemental Spirit herbs and two Lightning Elemental Immortal herbs. Other than the herbs, he had a few other materials that also had the two elements such as some Mountain Peak Jade that was formed under the sharp winds of a mountain peak and the lightning of a storm.

But having progressed the other cores, Lin Mu knew for sure these will be barely a drop in the ocean.

~Sigh~

'May as well use them.' He thought to leftism and started with the Wind Core.

Lin Mu took out some Wind Elemental Spirit herbs, which were the lowest quality wind elemental material he had. It was a herb called as Breeze Grass and was used to make Wind Resistant Armor and clothes. It wasn't meant for consumption but it could still be used for the Wind Core.

~SHUA~

The Omnicore Ascendancy worked as the bunch of Breeze Grass broke down into Azure Wisps of light that were immediately sucked into Lin Mu's hands. He had gotten decently good at using Omnicore Ascendancy and as such his speed of absorbing these elemental energy wisps had improved a lot. It took him a fraction of a second to absorb them, as compared to before when it took him a few seconds to do the same.

~FUA~

And when the Azure wisps entered his body, they were guided into the center of his chest under the control of the Omnicore Ascendancy Technique. It reached an area right below his lungs and above his intestines, entering a wide and flat organ.

This was none other than Lin Mu's diaphragm.

Once there, the Azure Wisps collected in the center of the diaphragm before coalescing together.

~HUU~

This caused Lin Mu to take a deep breath, his diaphragm expanding automatically. He felt like his lungs had inflated to the limit before it finally stopped.

'That… was different,' Lin Mu noted. 'When I formed the fire core in the heart, I felt a heat before and here my diaphragm moved on its own.' He wondered what was the reason for this.

Knowing that he needed to test it out further, he took out another bunch of herbs and repeated the process.

The herbs that Lin Mu was using this time were called as Cloud Foot Roots. As per their names, they had a cloud like shape and were very light. If one pressed them, they could cause them to burst, causing an air explosion that could very well shred clothes and cause injuries.

This was also a herb that was not intended for consumption, but was used in making expendable Spirit Weapons in the form of bombs. But what it did have was a lot of Wind Elemental energy in it. The only issue with it was this wind energy was unstable and could not be absorbed by cultivators. But the Omnicore Ascendancy did not care for that. It merely turned it all into pure Wind Elemental energy wisps and absorbed it.

~HUU~

Lin Mu's diaphragm moved once more, causing his lungs to expand uncontrollably. For a mortal, this would have been incredibly painful, but to a body cultivator like Lin Mu, it was the same as taking a normal deep breath. 'Strange… It can actually go beyond my control over my body and make my diaphragm work forcibly,' Lin Mu thought to himself.

~SHUA~SHUA~SHUA~

He absorbed more of the Azure wisps and saw the same process repeat. But he did notice that the effect was weakening over time. And when he had run out of all of the Mortal Wind Elemental materials he had, the uncontrollable expansion had long since stopped.

'Hmm… So it was dependent on the size of the Wind Core itself.' Lin Mu thought to himself, as he gazed at the sand grain sized core.

Before this, the core was microscopic and every time more energy was added to it, it caused his diaphragm to react, but now that it had reached a somewhat 'visible' size, it had stopped.

'A matter of stability, perhaps?' Lin Mu reckoned.

Lin Mu looked at the other wind elemental materials that he had left in his ring and knew that he shouldn't use them.

'It'll be a waste if I use them right now when I can still use a lot of mortal materials,' Lin Mu thought to himself. 'I'll pause this for now and make it a priority to collect more of them later along with more Immortal materials,' He decided.

With the Wind Core progressed to a certain point, Lin Mu decided to try the Lightning Core too.

For this, he only had six spirit herbs of the Lightning element and a few more materials.

But Lin Mu was disinclined to use those materials.

'It would be a lot better to keep them for other uses. I'll need them for Formation Arrays and more.' Lin Mu thought as using them would not bring him much benefit right now anyways. The sheer quantity he needed was massive and these would be a few drops in a colossal ocean. 'Its best to only use surplus materials for Omnicore Ascendancy or those that I really have no use for,' Lin Mu reckoned.

As such, Lin Mu only used the six herbs that he had.

The herb he started with was called as the Spark Leaf Herb and was something that created sparks if one smashed it. It was used as a stabilizing agent with other herbs in making pills and was of rather low quality.