And yet, it was precisely this cost that made the move so formidable.
The Dao Marks were embedded into the air, forming a special battlefield that was extremely difficult to destroy. Once a Gu Immortal entered it, every passing thought would be converted into Star Thoughts, which in turn manifested as the Ten Thousand Stars Flying Fireflies. The longer the battle dragged on, the stronger the technique became. It was a method of cleverly turning the enemy's own power against them, redirecting it as a weapon to strike back.
For the opposing Gu Immortal, the sensation was utterly revolting—like lifting a rock only to drop it on your own foot, or thrusting your own blade into yourself.
Having grasped the secret of how Ten Thousand Stars Flying Fireflies operated, Fang Yuan understood something else as well.
No wonder, throughout history, Dong Fang Chang Fan had primarily relied on scheming and calculation. Only when he had no other choice would he resort to combat, deploying this very move—Ten Thousand Stars Flying Fireflies.
Because even Dong Fang Chang Fan, the number one Wisdom Path Gu Immortal of the Northern Plains' current era, could not use Ten Thousand Stars Flying Fireflies as a regular technique—the cost was simply too enormous.
Once Dao Marks were expended, they did not recover on their own. The sources for acquiring Dao Marks were also extremely narrow; the vast majority of Gu Immortals could only obtain significant quantities of them by surviving tribulations.
"This move, Ten Thousand Stars Flying Fireflies, is nearly on par with my own current killer move, Myriad Self. Of course, Myriad Self still has enormous room for growth—something Ten Thousand Stars Flying Fireflies can't hope to match. I have no Wisdom Path Dao Marks on my body. Unless I walk the Wisdom Path in the future, I'll probably never be able to use this killer move for the rest of my life."
Of course, there was another critical factor besides that.
The Ten Thousand Stars Flying Fireflies killer move required three Wisdom Path Immortal Gu as its core.
Fang Yuan didn't have a single one.
When Dong Fang Chang Fan had been defeated, he had detonated every last one of his Immortal Gu, leaving nothing behind for Fang Yuan.
Of the three Wisdom Path Immortal Gu, the one Fang Yuan wanted most was the Star Thought Immortal Gu.
This Wisdom Path inheritance contained over a dozen Immortal Gu recipes, including the recipe for the Star Thought Immortal Gu itself, along with the insights of how past inheritors had refined it and many notes on their failed attempts!
Once he had the Star Thought Immortal Gu, Fang Yuan would no longer need to go through tremendous effort to slowly stockpile Star Thought Mortal Gu.
According to the records in the inheritance: by expending one Green Grape Immortal Essence through the Star Thought Immortal Gu, at least one hundred thousand Star Thoughts would be produced.
Naturally, if Fang Yuan were to activate the Star Thought Immortal Gu, the number of Star Thoughts he obtained would certainly be fewer than one hundred thousand.
After all, every past inheritor of the Wisdom Path had carried Wisdom Path Dao Marks on their body, which amplified the Star Thought Immortal Gu's effects. Just as Fang Yuan had Strength Path [Dao Marks], allowing him to use the Great Hand Seal with a full twenty percent boost in power.
Twenty percent was considered modest. For most powerful Gu Immortals, the Dao Marks on their bodies could multiply the power of Immortal Gu and Immortal-level Killer Moves by factors of two, three, four—even ten times, a hundred times!
The reason the gap between Eighth Transformation and Seventh Transformation was so enormous came down to Dao Marks as one of the primary factors.
The higher one's cultivation, the more terrifying the tribulations. But once survived, the Dao Marks gained were correspondingly greater.
Fortune hides misfortune; misfortune lurks behind fortune. Looking at it from another angle, the fact that Heavenly Tribulations and Earthly Calamities grew more powerful was, in a sense, a blessing.
It could be said that once he obtained the Star Thought Immortal Gu, the obstacles in Fang Yuan's calculations would be drastically reduced. He would no longer need to carefully ration his Star Thoughts, using them with painstaking frugality.
Moreover, with his current financial resources, he could afford the expenditure.
But the unfortunate truth was that while Fang Yuan could sustain the cost of using Immortal Gu, he lacked the wealth to refine them.
Even after profiting from a few transactions, he was still a long way from having enough to refine an Immortal Gu.
Immortal Gu were unique—fragments of the Grand Dao's laws. Refining them demanded enormous quantities of immortal materials and Immortal Essence Stones.
More critically, you couldn't possibly prepare just one set of materials for refining an Immortal Gu. You had to prepare many sets, because the success rate of refining an Immortal Gu was pitifully low!
Dong Fang Chang Fan had been a titan of his generation, the Northern Plains' foremost Wisdom Path Gu Immortal, commanding a supreme-level power for many years while secretly trading with the Immortal Crane Sect and receiving substantial support. Even so, at his peak, he had only possessed eight Immortal Gu.
Among those eight, there were side-path ones like the Meridian Blood Immortal Gu and the Shadow Splitting Immortal Gu. Of the dozen or so Immortal Gu recipes recorded in the Wisdom Path inheritance, he had successfully refined fewer than half.
Then there were figures like Old Ancestor Snowy Beard and Lady Ten Thousand Years—the former currently the Northern Plains' strongest Eighth Transformation combatant, the latter one of the Northern Plains' four great Refinement Path Gu Immortals. Both could be considered to have deep foundations and sprawling resources.
Yet even to refine the Eighth Transformation Fortune Equal to Heaven Immortal Gu, even with Ma Hongyun already in hand to save many steps and resources, doing so would still consume nearly their entire fortune—a true all-or-nothing gamble!
As for Fang Yuan's current situation, wanting to refine an Immortal Gu was something he shouldn't even dream of. The mere thought was pure fantasy.
Beyond the Star Thought Immortal Gu, the Immortal-level Killer Move Fang Yuan valued most was called Star Mist Veil.
Its function was to envelop the Gu Immortal in a permanent shroud of starlight mist, concealing their appearance and form so that outsiders could not see them clearly.
That, of course, was merely the cosmetic effect.
The true primary function lay in its ability to obscure heaven's secrets. When other Wisdom Path Gu Immortals attempted to calculate this particular Gu Immortal, they would find themselves lost in a haze, receiving only vague and contradictory answers.