Even if the wood splinters were from just normal trees, it didn't mean that they had no wood element in them.
All things in the world contained energy and had an inclination towards one or more elements. Just because one couldn't see it or make use of that energy didn't mean that it didn't exist.
Of course, even for cultivators, refining this energy from mortal materials was not a viable option. They might be able to extract some energy, but the effort and time needed to do that would not be worth it. And even that tiny amount would be extracted from a massive amount of raw material.
It was the same as using hundreds of kilograms of rose petals, just to extract a few milliliters of pure rose essence oil.
But in the case with Lin Mu, he didn't need to put in as much effort. Omnicore Ascendancy directly broke down materials into their base elements, thus Lin Mu wouldn't be spending too much time in doing it.
"Time to start." Lin Mu muttered and raised his hand towards one of the large piles of wooden splinters.
~SHUA~
The wooden splinters flew up from the pile and moved towards his hand as he activated Omnicore Ascendancy. The mnemonic worked as intended and the wooden splinters turned into nothingness.
"No wisps this time..." Lin Mu furrowed his brows.
The splinters were just breaking down into nonexistence. But Lin Mu didn't stop there, continuing the process and letting the stream of wooden splinters move towards his hand.
~roooooo~
The splinters breaking down created a strange droning sound that filled the otherwise silent insides of the ring. It took an entire minute and possibly hundreds of kilograms of Wooden Splinters before a single green wisp appeared.
"Oh!" Lin Mu watched as the tiny green wisp entered his body before finding its way to his liver.
There it clumped with the mung bean sized core and became a part of it.
"Guess I'll just have to keep on doing it until it doesn't work." Lin Mu said before starting again.
~shua~
A stream of wooden splinters flew towards his hand and started breaking down. For ten entire minutes, not even a single wisp of energy was made, making Lin Mu wonder if he had indeed hit a limit since it hadn't taken this long last time.
~sha~
But just a few seconds later, another wisp of wooden element was formed.
"Not yet." Lin Mu continued, draining hundreds of kilograms of splinters.
Minutes turned into hours, as Lin Mu depleted almost all of the 'waste' wooden splinters that he had gathered over the years.
By the time he was done, it was almost the last day before the 30 day period of travel.
~huu~
Lin Mu let out a breath and took a break, checking on his progress.
"All that wood and it's barely grown by a couple grains of sand in size..." Lin Mu estimated.
The efficiency was certainly low but the cost for it was negligible. All the wooden splinters he had consumed would probably be a fraction in cost as compared to just the low grade spirit herbs he had consumed.
And yet the amount of energy he had obtained from them was the same. 'Other than the sheer quantity needed, the cost itself is negligible for it.' Lin Mu thought. 'And I still don't know if I have hit the limit for the splinters.' He realized that estimating the limit for very low quality materials was going to be hard.
He looked at the other piles of similar quality materials and thought about what to do. There were still piles of wood chunks left after all.