Under normal circumstances, there were only two criteria for determining an experienced 8th Rank cultivator. First, the depth of one's Small Universe needed to reach a certain level.
Typically, for at least two thousand years after advancing to the 8th Rank, one could not be considered an experienced 8th Rank.
Two thousand years was enough time for an 8th Rank to consolidate their foundation and bring out the full power an 8th Rank Open Heaven should possess.
The second criterion was combat experience against enemies.
No matter how powerful one's foundation, without battle-hardened experience against real opponents, one would always be restrained in combat, unable to unleash their full strength.
The human 8th Ranks on the Ink Battlefield, with the exception of a few who had only recently advanced, were mostly experienced 8th Ranks. After breaking through, they had fought the Ink Clan while simultaneously cultivating, honing their mastery of power through combat. So none of them suffered from the problem of possessing power they couldn't wield.
Yang Kai was an exception.
He had advanced to the 8th Rank within the River of Time, then spent a full two thousand years cultivating before breaking free.
Immediately after emerging from the Great Sea Phenomenon, he had clashed with the Goat-Headed Royal Lord and even slain him. But in that battle, there had been a considerable gap in their respective strength, forcing Yang Kai to push himself to his absolute limits. He had even activated the Sacrificial Soul Spike four times in succession, leaving himself in a state of delirium. He didn't even remember how he had killed his opponent — when he came to, he found himself holding the Goat-Headed Royal Lord's severed head.
This time was different.
Domain Lord-level Ink Clan powerhouses were neither too strong nor too weak for him — just right to serve as his whetstone.
After killing two Domain Lords in succession, he hadn't rushed to finish off the third. Instead, he had used that remaining Domain Lord's strength to hone and familiarize himself with his own dramatically increased power.
In particular, the numerous Dao Realms he had absorbed and refined within the Great Sea Phenomenon — tempering them through fierce battle would make them smoother, more instinctive to wield.
That was precisely why the Fang Domain Lord had sensed Yang Kai's displayed power growing ever stronger. The number of Dao Realms Yang Kai now commanded was simply too vast — so vast that he couldn't bring all of that power to bear at once.
He desperately needed a battle like this.
That was why he had chosen to take injuries in order to quickly kill the first two Domain Lords.
Half a day later, despair took root in the Fang Domain Lord's heart. This battle had gone from being evenly matched at the start to his complete disadvantage now. He was stumbling toward the abyss, step by step.
His heart was filled with bitter anguish.
The tide of battle had turned completely. Yang Kai attacked at an unhurried pace, still honing his power, while the Fang Domain Lord fought with the desperation of a cornered beast. He knew with grim clarity that the longer this dragged on, the stronger his enemy would become. Once some threshold was reached, that would be the end of him.
However, battle was not always something sheer desperation could overcome.
After another half day or so, the Fang Domain Lord's aura had weakened beyond recognition. Wounds, large and small, covered his body in dense clusters. Ink Blood and Ink Force leaked from the gashes, and his entire bearing had slumped to a level below that of a Domain Lord.
In this moment, he envied his two companions immensely. At the very least, they had died cleanly.
He, on the other hand, was being sliced apart by a dull blade, enduring both physical and mental torture.
Knowing his death was certain, the Fang Domain Lord hardened his heart, abandoned all defense entirely, and charged at Yang Kai with savage abandon.
A dozen breaths later, a long spear pierced into his eye socket. Numerous Dao Realms detonated within, churning his skull into a bloody pulp. The ferocious expression on the Fang Domain Lord's face gradually softened, bearing an almost relieved look, as the light in his eyes rapidly dimmed.
Yang Kai withdrew his spear and furrowed his brow slightly. He was, to some degree, dissatisfied with his current strength.
Setting aside the battle with the Goat-Headed Royal Lord — in that fight, he had lost consciousness entirely by the end, his body acting on pure instinct to slay his enemy.
Fighting these three Domain Lords had revealed his shortcomings.
At the 7th Rank, he could crush anyone at the same level. No matter how powerful a Lord was, they were like children before him, utterly incapable of fighting back.
But now, at the 8th Rank, it was difficult to replicate the dominance he had enjoyed at the 7th.
To quickly kill the Charm Domain Lord and the Talon Domain Lord, he had paid a considerable price. And as for this last Fang Domain Lord — the less said the better. Even accounting for the fact that he had been using the fight to hone his power, it was still unsatisfactory that it had taken so long to finish him off.
According to the intelligence he had gathered during the expedition, all three of these Ink Clan Domain Lords could be classified as Innate Domain Lords — born directly from Royal Lord-level Ink Nests. They were stronger than ordinary Domain Lords who had advanced through cultivation, all belonging to the same tier as Chekong.
This was already the pinnacle of an Ink Clan Domain Lord's strength.
In other words, he could be called invincible among his peers now — but he was still far from the level of absolute domination!
Though when he thought about it, he had only been cultivating for two thousand years since advancing to the 8th Rank. His Small Universe's depth hadn't yet reached its ceiling. Once he grew to the peak of the 8th Rank, crushing his peers should pose no problem.
Additionally, he had identified his biggest current problem.
He commanded too many Dao Realms!
To break free from the Great Sea Phenomenon, he had been forced to absorb those dark currents one by one, enhancing his comprehension across these various Daos.
He had collected and refined far too many dark currents, achieving attainment in one Dao after another. Commanding many Dao Realms meant he had a wealth of techniques to deploy against his enemies — and that was a good thing.