James didn't rush into the gene fusion immediately. Instead, he shadowed Mom and Dad as they conducted a sweep of their new kingdom.
The Xenosmilus pair hadn't vanished; they had merely retreated to the eastern flank of the territory, clinging to roughly half of the land. A thicket of dense brush served as the makeshift border. James's family claimed the resource-rich western side, while the grieving Xenosmilus pair took the east. For the rivals, this retreat was likely a temporary survival tactic. It wouldn't be long before they tried to reclaim what they had lost.
Along the way, Dad and Mom marked the landscape with a violent intensity. They sprayed urine, rubbed scent glands against the limestone, and stood on their hind legs to rake deep gouges into the bark of ancient trees. They were methodically erasing every trace of the previous owners. Once the perimeter was secured, they scouted for a suitable den.
Night fell.
While the rest of the family slept, James retreated to a dark corner of the cave and summoned the system interface.
---
[DING! Spending 100 Gene Points. Commencing Gene Replication.]
---
This time, the process was grueling. Unlike the quick sage time of previous upgrades, this was a total biological overhaul. A searing, molten heat surged through his veins, vibrating through his muscles and bones as if his entire frame were being broken down and reforged in a furnace.
---
[DING! Integration complete. Xenosmilus genes merged. Smilodon Gene Level increased!]
---
By the time the heat dissipated, James's eyelids felt like lead. Exhaustion hit him, and he slipped into a deep, dreamless sleep before he could even check the results.
When he finally opened his eyes, the sun was already dipping toward the horizon, painting the cave walls in a bloody orange hue.
"I slept that long..."
He hauled himself up, his head still swimming. The hangover from this particular upgrade was heavy. He immediately performed a self-diagnostic.
To the naked eye, the change was subtle, but to James, it was profound. He felt denser. His frame had expanded; his body length now hit 180cm, and his weight had officially crested the 150kg mark. This single upgrade had essentially hyper-accelerated two months of natural physical development into a single night.
The system panel reflected the new reality:
---
--- STATUS ---
[Name]: James
[Species]: Smilodon fatalis (Male)
[Age]: 1 Year
[Smilodon Gene Level]: Lv2 (0/100)
[Strength]: 82 (+)
[Agility]: 77 (+)
[Physique]: 80 (+)
[Gene Points]: 30
[Integrated Genes]: Flat-headed Peccary, Clouded Leopard, Giant Hyena, Shark, American Alligator
[Reinforced Parts]: Skin Hardness (Lv1), Tail (Lv1)
[Added Abilities]: Bite Force (Lv1), Tooth Regeneration (Lv1), Immunity (Lv1)
---
"A new category... Smilodon Gene Level. System, what does Lv2 signify?"
---
[Lv2 Smilodon Genes mean the Host's attribute caps are now double those of a standard Smilodon. Your maximum physical potential has been heightened.]
---
James felt a jolt of pure adrenaline. Double the attributes?
This wasn't just incremental growth. If he maxed out his Strength, Agility, and Physique at twice the natural peak of his species, he wouldn't just be an apex predator—he would be a monster. At full potential, he could likely dismantle four or five adult Smilodons simultaneously. He would outclass even the American Lion. On this continent, only the Giant Short-Faced Bear would remain a credible threat.
And this was only Lv2. What happened at Lv3 or Lv4?
"To level up further, I need more genes from the Machairodontinae subfamily."
James calculated his options. In Pleistocene North America, his choices were limited. Xenosmilus was here, but Dinofelis was a ghost on the verge of extinction.
Homotherium and the massive Smilodon populator were the real prizes, but they dominated South America.
'I'll have to head south eventually." It was a long journey, but the promise of breaking the limits of his species made it a necessity.
The family had claimed the Stag-moose carcass originally hunted by the Xenosmilus. Waking up famished, James tore through nearly 30kg of meat in a single sitting, his appetite now rivaling that of his parents.
As he finished his meal, he felt a heavy, unsettling gaze on him. He looked up to find Dad watching him. Dad had stopped eating, his eyes fixed on James with a strange, brooding intensity. He was huffing, his breath rhythmic and heavy, his tail twitching with an agitation James didn't recognize.
The hair on the back of James's neck stood up.
"What's the problem? Did I eat too much?"
He looked down and realized he had drifted into Dad's prime feeding spot. In their family, hierarchy was everything at the kill. Dad and Mom always took the choice organs and the best cuts. Usually, James was careful to wait his turn or stay in his lane. Zack and Zoe had already learned the hard way that encroaching on Dad's meal earned a swift, painful lesson.
Today, in his post-upgrade hunger, James had forgotten.
"ROAR—"
Dad stood up, a low-frequency vibration rumbling in his chest. It was a sound of warning and challenge.
James didn't want a civil war. He dipped his head and backed away, yielding the spot. Dad's eyes lingered on him for a moment longer—a sharp, measuring look—before he settled back down to finish the meat.
Zack and Zoe were oblivious, still greedily stripping bone nearby. But Mom was silent. She watched James with an expression that seemed to carry a heavy weight. James looked at her, and in that moment, he understood the unwritten law of the wild.
He was no longer a cub. He was a competitor. His time in this den was running out.