It somehow worked but felt like hell!! The reason is the climb was worse than the running.

Eren’s fingers found grooves in the rocky parts that his old hands would’ve slipped off of but his Feline Enhanced Climbing skill turned every crack and ledge into a grip point.

His toes dug into surfaces that shouldn’t have been climbable and his body pulled itself upward with a fluidity that felt borrowed from something that wasn’t him. Maybe his new inner cat parts was giving him help or some skill was doing the work but this motions were new to Earthling Eren.

The mountain cliff side was steep enough that a normal person would’ve needed rope and harness and probably a therapist afterward but his Absolute Equilibrium kept his center of gravity so stable he could’ve been climbing a staircase for all his balance cared.

[Congratulations! Your skill Climbing (Basic - Feline Enhanced) levelled up]

-Level 8 > Level 9

The notification appeared while he was hanging from a ledge with three fingers and one foot jammed into a crack. It became Level 9 in this somewhat crazy mission of his!

One more threshold event or enough self realization and that skill would evolve to Evolution League 2 and jump to Uncommon quality hopefully.

But he couldn’t think about that right now because the ledge under his foot was crumbling and the drop below was about sixty meters of nothingness. He wasn’t afraid of heights anymore with the new skill’s op passive effect but still it was deadly if he fall from this much height. Even his his Featherfall Reflex skill wasn’t enough for this yet.

The wyvern cave entrance was above him and a little to the right side. A dark gash in the cliff face maybe fifteen meters wide and eight meters tall surrounded by deep scratch marks in the stone and old bones wedged into crevices.

Something very large could fly and went through that opening regularly which he saw happening in his crazy running time to this mountain region.

He pulled himself up past a loose shelf of rock, found a flat section of cliff face and used it to push off sideways toward the entrance ledge. The jump was maybe three meters of horizontal distance over a forty-meter drop and his body performed it like it was stepping over a puddle. It was too easy with his new body which was lighter, stronger and thinner...

I am losing weight too fast..

His feet hit the ledge and his weight settled instantly, perfect balance, zero wobble, the Absolute Equilibrium skill or his new evolved body doing everything automatically.

[Congratulations! Your skill Absolute Equilibrium (Uncommon) levelled up]

-Level 2 > Level 3

He got his answer that it was the skill’s doing.

Eren stood on the ledge and looked at the cave mouth and it was pitch black inside. The afternoon light reached maybe two meters past the entrance and after that there was nothing.

Then his eyes did something. It started behind the iris, a warmth that spread across the inside of his eyeballs like someone had turned on a tiny heater behind each pupil. His vision shifted, not gradually like eyes adjusting to a dark room after a few minutes but all at once, like flipping a switch.

My eyes just... adapted?

The darkness inside the cave resolved into shapes and gradients and textures. Not color exactly but depth, the way a cat sees at night where everything becomes shades of grey-blue and the outlines of objects sharpen instead of blurring.

He could see twenty, maybe thirty meters into the tunnel. Rough stone walls, a downward slope, a curve to the left where the passage widened.

"So thats how they see in darkness..Weird but beautiful."

He didn’t have time to appreciate it because a rock the size of his fist came from below and behind him.

His Predatory Reflex caught the movement before his conscious brain registered it and his body leaned sideways so fast his shoulder scraped the cave wall. The rock thrown from too far away went past his head close enough that he felt the wind of it brush his hair and cracked against the stone ceiling inside the entrance!

"What the hell was that?" He said even if it was dangerous talking on the road of Wyverns’ front gate.

He looked down and saw those two fu*ers..They were already climbing after throwing the previous rock.

The big male was about thirty meters below and the female was ten meters higher and to his left, moving across the rock face with a speed that made his own climbing look clumsy. Her hands and feet found grips in the cliff like she’d been born on vertical surfaces and the rock she’d thrown had been grabbed and hurled mid-climb without breaking stride.

Both of their faces were turned up toward him and even from this distance Eren could see it. The same intelligent hatred in those eyes. Focused and personal and absolutely nothing like how an animal looks at prey which was strange.

Why..?

Eren was one hundred percent certain he hadn’t done anything to these two.

This morning after his evolution he’d messed with some fire-element apes and stolen fruit from an elemental gorilla clan but those were southern creatures tied to their own territory. These northern rock gorillas had no connection to any of that.

I didn’t do anything to you. I didn’t touch your territory. I didn’t hurt your family. I didn’t even know you existed until you showed up at my tree. So what the hell do you want from me?

A month ago he probably would’ve tried to understand. He would’ve looked for a way to deescalate or redirect or just run far enough that they gave up which he somehow still did.

But something had shifted inside him since the evolution and after two hours of being chased by two creatures that refused to stop. And he was done being reasonable!

If these things wanted to chase him until one side of them died then fine... He’d make sure it was them.

The old Eren from Earth would’ve felt bad about that thought. This Eren ran his tongue across his slightly sharper canines and felt nothing but cold certainty.

If I die they die first. And if I live they die anyway. That’s the only deal left.

He turned and walked into the dark.

..

The tunnel went down and then curved and then split into three branches and then two of those branches split again and within five minutes Eren was inside a maze of rough-hewn stone passages that went in every direction including up and down.

Most of the inner tunnels or dead ends were simply stupid in simple words.

Like some of them wide enough for a wyvern to pass through. Others were barely wide enough for him to squeeze sideways. Some had smooth floors from decades of something heavy dragging across them. Others had no floor at all, just crevices dropping into darkness.

There were too many bugs and weird dark shit he didn’t want to mess with or simple try his escape from death chances. But if he didn’t do something to those beings, they would let him pass from their terrritories like he didn’t matter to them.

"Thank you kind sir.." He muttered with a slight grin and run past a one meter long dwarfy tunnel and found a bigger one with lots of fresh air.

The air currents from this side was better for breathing and he let out a sigh with his new eyes resembles a cat’s in darkness.

He moved fast but quiet, his bare feet making almost no sound on the cold stone. The goblin filth on his skin had dried and the smell was fading from pure sensory overload, his nose had stopped thinking it as separate from his own body scent with his own logic.

Maybe he still felt dirty in a way that made his chest tight but the panic was manageable now, pushed down under layers of exhaustion and focus.

But here was something very wrong with his body now beyond tiredness. There was a headache building behind his eyes that wasn’t like any migraine he’d had on Earth.

This one was deeper, inside the base of his skull like something structural was complaining. His joints ached with a dull heat that had nothing to do with exercise and his fingers tingled even when he wasn’t gripping anything.

My body is telling me to stop. Not "I’m tired" stop but "something is actually wrong" stop.

He’d heard somewhere that humans had internal warning systems, proprioceptive signals that told you when you were pushing past safe limits. Pain and fatigue and nausea were the obvious ones. But there were subtler signals too, the ones that most people ignored until something broke.

Animals were different though. Most wild animals hid their pain because showing weakness meant getting eaten. A wounded deer didn’t limp if a predator was watching. A cat with a broken rib would purr and act normal until it either healed or died.

Is that what’s happening to me? I feel like absolute shit but some part of my brain is refusing to admit it because admitting weakness right now means dying but I wouldn’t admit it even if there was no Gorillas coming after me..

He was still moving, still fast and still quiet.

His Primal Senses scanned every tunnel and crevice ahead of him for heat signatures and his Tracking skill picked up vibrations through the stone floor, heavy footsteps somewhere behind him, maybe two or three minutes back. The gorillas had entered the tunnel system.

[Congratulations! Your skill Primal Senses (Uncommon) levelled up]

-Level 7 > Level 8

The level-up sharpened everything mid-step. The tunnel walls went from shapes to textures to individual mineral deposits he could almost name. He could feel the air pressure changes that meant open spaces ahead versus dead ends. And something else, a directional sense that tugged at the back of his awareness like a compass made of instinct instead of magnetism.

He stopped walking because something was off.

Wait!

He started thinking what was wrong and what the skill was telling him now. In a few seconds, he realized the situation.

I’m not going deeper into the mountain. I’ve been moving outward and upward this entire time like a staircase!

He checked his memory of the last several turns and the directional pull confirmed it.

Eren has been spiraling toward the surface side upwards, not away from it. The tunnels had been leading him up and toward the cliff face he’d climbed, just higher.

Way higher.

I’m still on the same side of the mountain but hundreds of meters above the entrance probably. The wyvern nest isn’t spread through the walls like I guessed and now I can’t even get in the middle of the mountain because of this stupid passages.

The gorillas were still behind him somewhere in the lower tunnels. They were too big for the narrowest passages so they’d have to go around and that bought him time.

He kept moving upward but hopefully this time, he would find a way to kill these two crazy animals.