As it turned out, he was right to say only time will tell if he is really cultivating with heavenly lightning or not. This was because after an hour of baking his golden core in heavenly lightning and life force, he was able to come to a conclusion about the feasibility of his project.
He said to himself, "There is good and bad news. The good news is that I can really cultivate lightning. The bad news is that it is going to consume a lot of life force."
There was some bad news, but it wasn't enough to stop him from smiling.
After running out of life force to continue the project, he checked his golden core to see if the strengthening that he felt was permanent or not. When he saw that the strengthening was permanent, he couldn't stop smiling.
The best part is that actively cultivating with heavenly lightning for so long is training both the lightning vessel sigil technique and the wood vessel sigil technique. After all, the best way to master something is to use it over and over again for a long period of time.
Of course, the lightning vessel sigil technique is growing at a faster rate because he is using it to attract lightning, store lightning, and cultivate at the same time. But the growth of the wood vessel sigil technique is also encouraging.
At the rate at which the wood vessel sigil technique is growing, he will need to make fewer and fewer trips to the forest to get more life force. These are the reasons why a single bad news about the high cost of cultivating with heavenly lightning is not enough to make him sad.
He stopped calling lightning so that he could go and get more life force. This made the storm in the sky disappear, so light from the sun was able to finally reach him.
The increased visibility allowed him to see the three patriarchs standing some distance from him and looking at him. So he quickly rose up to greet them.
He bowed his head to them and said, "Greetings, honored patriarchs."
Thunder Drake nodded in acknowledgement and said hurriedly, "Before we say anything, you must answer this question. What were you just doing?"
Arthur replied respectfully, "I was cultivating."
His answer made Sword Flash smile. But Thunder Drake wasn't satisfied with his reply.
So Thunder Drake said to him, "Just to be sure, and you must not lie to us about this, were you cultivating with heavenly lightning?"
Arthur nodded as he said, "Yes, sir. I was cultivating with heavenly lightning."
Sword Flash gave a triumphant laugh and said, "I said so."
Lady Evergreen said, "Hold on. My turn."
Then she asked Arthur, "Were you using life force to cultivate, too?"
Arthur was wondering why they were asking him so many questions, but he still replied quickly, saying, "Yes, I was."
This made Lady Evergreen smile and say, "Aha. I was right, too."
Then she said to Thunder Drake, "Pay up, sucker."
From here on, Arthur couldn't hear what they were saying because they were communicating with each other using their spiritual sense.
Thunder Drake sighed in defeat and said, "I guess I lost the bet."
Then he shook his head in disbelief and said, "But I still can't believe it. It doesn't make sense. It is common sense that heavenly lightning can't be used to cultivate."
Lady Evergreen said smugly, "I don't care if it makes sense or not. All I can say is that you lost the best and need to pay me as soon as possible."
She, too, doesn't know how Arthur managed to accomplish what shouldn't be possible. But as soon as Sword Flash said that Arthur might be using the lightning to cultivate, she agreed with him.
Apparently, she doesn't need to know how geniuses behave for her to know what they are capable of doing. She only needs to follow the lead of another genius, and she will be right about what geniuses are capable of.
Sword Flash, on the other hand, was able to guess why Arthur was able to withstand heavenly lightning and cultivate with it without turning to dust. This was why he made the proposition that Arthur was cultivating with heavenly lightning.
He said to Thunder Drake, "I wasn't sure at first, but after examining him again, I can be 80% sure why he was able to cultivate with lightning. The trick lies with his perfect core, his two-element based core, and the magnetic field produced by his core."
"Of the three of them, I believe that the possession of a magnetic field accounts for 50% of his success. Without it, he simply wouldn't be able to direct the heavenly lightning to his core without turning to ashes. The magnetic field produced a boundary for directing and controlling the heavenly lightning."
"The second most important factor is the fact that he has a perfect core. His core has no defects, so it was able to withstand the power of the heavenly lightning and even grow stronger with it."
"Without the perfect core, even the magnetic field wouldn't be able to save him. His core would have shattered under the impact of heavenly lightning. After all, heavenly lightning is at least a rank 7 power."
"As for the wood element and life force, they are responsible for healing him and helping him withstand the heavenly lightning for so long. But without them, he should still be able to cultivate with heavenly lightning."
Lady Evergreen shook her head and said, "He might be able to cultivate without the wood element in his core, but without the wood element and its perfect synchronization with lightning, he wouldn't possess the magnetic field in his core, so he wouldn't be able to direct and control heavenly lightning at all."
Sword Flash nodded in agreement and said, "That's true. Without the magnetic field, even if he had a perfect core, he wouldn't be able to protect his body from the heavenly lightning and would have destroyed himself long before the Heavenly lightning reached his core."