Seated on a bench he had quickly crafted using the fallen tree, Aito absorbed one soul core after the other. 

The absorption process was the same as absorbing mana beads. Either eat it or drain it. The empty core would then disappear because what maintained its physical state wasn't there anymore. 

Each time he sucked in the mana and soul, he felt that something was added to his own core. After emptying the fifteen cores that were his share, he could feel that he was almost at his limits. It was akin to a filled stomach, if he were to abuse it, his soul core would burst into pieces. 

He needed to give his soul enough time to digest the goblins' souls. Inside his bosom, the goblins' souls were trying to fight a pointless battle, running away from the human soul sucking their life.

Well, there were already weakened because of the death of their body, so there was nothing they could do about it. Aito's soul only needed time to steal their life force. 

The process of leveling up this way was gruesome through and through. One would first need to first kill the physical body of a living being then "kill" its soul and absorb its life force to make it one's own until nothing remained of it. 

Many closed their eyes on what this truly was: eating souls to get stronger. Those who didn't close their eyes on this topic were either forced to shut their mouth to avoid sullying the common point of view or simply didn't live in the society led by the gods. 

An hour later, after eating a meal, Aito felt himself bursting with energy like never before. It was like he had grown stronger somehow. Not by much, though. A level up would require much more goblin souls to absorb. If it were that easy to level up, every challenger would have done it by now.

Using some of the bottles of antidotes and poison they had acquired until now, Aito started his poison resistance training. 

Being reluctant to try it out first, both siblings kept watch while their partner was painfully grabbing his stomach before being paralyzed. Having ingested the antidote beforehand, the paralysis stopped quickly. 

Noticing no difference in his status window, Aito repeated the process again and again to finally see the blue window he had been waiting for. 

[Congratulations! You have acquired the passive skill Poison Resistance Lv1!]

"How is it?" Ogoro asked. 

"Painful, but worth the trouble," Aito said. 

With his body at level 3, it didn't take long to develop poison resistance, a few hours at most. 

"Who's next?" 

Seeing as he was alright, Sheyla took the next turn while her brother and Aito stood guard.

Since her body wasn't on the same level as Aito, it took much longer, something that wasn't originally planned. Understanding this, Aito pushed back their cave expedition for the next night. 

He indeed wanted to explore that cave as fast as possible to grab the hidden item inside that surely would come in handy later, but rushing things wouldn't do them go. 

Aito and Ogoro had to take turns keeping watch through the night until the next day. 

Sheyla's composure didn't look great in the morning. She was pale, appearing frail. Ogoro helped her to rest before starting his own poison resistance training while Aito kept an eye out for potential troubles. 

Some wondering goblins had come out of the cave from time to time only to find a gruesome ax-welcome awaiting them. 

By the early afternoon, Ogoro got Poison Resistance Lv1. It was faster than his sister thanks to his level 2 body. 

Once done, the siblings who were still tired from ingesting poisons, then antidotes rested while Aito trained his new skill moderately, keeping at least half of his stamina in reserve in case any unforeseen events happened. 

Aito brought down some trees in their surroundings with Impact. By now, he had told the siblings he had acquired a new skill, so they weren't as shocked as before. Still, punching the shit out of a tree was an uncommon sight for them. 

The light of their second day on the fourth floor progressively deemed, announcing the coming of the night and the cooldown period. 

Aito and his team used that moment to stop whatever they were doing and replenish their strength for an hour while observing the movements of "nearby" challengers from above using Sheyla's enhanced vision from time to time. 

The sun finally "set" on the fourth floor as the staircases closed. 

Aito took out his magic torch from an inventory bag and gripped it firmly in his left hand before deploying his shield entirely. The light crystal barely stuck its head out of the shield's protective boundaries to shine on the surroundings as he entered the secret entrance of the underground tunnels. 

Behind him, the siblings who had both chosen to have their light crystal fixed to their headgears followed him close by, on the lookout for potential danger. 

They ventured deeper and deeper into the heart of the mountain, going through myriads of tunnels, drawing arrows on the earth walls to find their way back if needed, dealing with a few groups of goblins. 

Their encounters with the green pests were growing more frequent the further down they went. 

Aito used the blurry knowledge from Gwen of the surroundings to lead the way. Thanks to that, they avoided quite a few dead ends, but not all of them. 

Advancing more cautiously than usual, they moved slower than they would in a more open environment. 

'I thought the hidden entrance directly led to the center without any detours. *sigh* Should have known it wouldn't be that easy.' Aito thought, turning back because of a cul-de-sac. 

In the darkness, around a seemingly black empty corner, dozens of yellow eyes were focused on their preys that dared ventured here. 

Feeling something was amiss, Aito halted the march and scanned the surroundings using his magic torch. 

'Did Intuition give me a false warni—' 

"Behind us!" 

The three of them made a swift turn. Ten goblins they had probably missed because of the darkness abandoned stealth to run towards them, weapon in hands. 

Sheyla promptly shot three bolts to neutralize those to the back. Ogoro used his short mode sword to deal with those closest to him. Aito arrived by his side on time to block a dagger strike and slice off a goblin's head. 

The fight was over in less than fifteen seconds. No goblins were allowed to escape. 

"Fuck, the little buggers surprised me!" Ogoro said. 

Sheyla didn't reply and simply glared at their surroundings, trying to pry open the darkness's secret. 

"Weird, I'm certain we should have seen them on our way here. How did they get past us?" Aito said. "We thoroughly scanned the tunnels and saw no traces of them before." 

"It's too dark, or it could also be illusions like the one you 'broke' at the entrance," Sheyla replied.

The possibility of illusions masking the presence of goblins was high. According to Gwen's memory, Aito knew there was a goblin shaman awaiting them down there. What made this goblin special was its ability to cast illusions. 

The rock blocking the hidden entrance had certainly been its doing. But it had been too real. 

Even if it had the power to cast realistic illusions, it should have taken the goblin shaman a considerable amount of effort. Well, it had two months to do so. 

This thought triggered one of Gwen's blurry memories, making it clearer, which Aito linked to his current goal. The goblin could indeed cast that kind of illusion by using its ring, a special item that was the reward for this floor and also his reason for coming here.

However, the item could cast two realistic illusions, more than that was impossible. So, the goblin probably had another such illusion somewhere. Maybe another one now since Aito got rid of the rock earlier. That wasn't certain though. 

Furthermore, the illusion couldn't be a living being, only unliving and unmoving things such as rocks could be cast. Meaning that the chance of a fake dead end to hide the goblin shaman's hideout was high.

The shaman's other illusions were much less realistic. A simple touch could disturb their flow and reveal them. 

Although, in this darkness, it could be hard to distinguish them. So, he thought about something simple, but that would slow down their advance even more. 

'I can't just use Fearless Aura until we reach our target. It would cost me too much aura. I also don't wish to reveal it to the siblings, not now at least.' 

Aito quickly pondered on the question and came up with a simple answer.

"Shit…, how are we even supposed to deal with those?" Ogoro asked. "Do we have to punch every wall like Aito did?" 

"Stupid idea," Sheyla said. 

"It would take too long," Aito replied. He shared the knowledge from Gwen's memory about the illusions then added, "Since a simple touch can disturb the illusions, we just have to touch the walls every meter or so. It will take some time, but better be safe than dead, hun?" 

It was a simple plan indeed. With no better proposition, both siblings nodded. They resumed their advance, touching the walls with their weapons every so often. 

A few minutes passed. They discovered a few other illusions that hid groups of goblins that were promptly dealt with. Those little creatures were easy to deal with, provided one didn't fall for their ambush. 

Aito had heard rumors about unpredictable ambushes in the tunnels that, no matter how prepared was a team of challengers, they would ultimately be surprised by goblins. 

The next illusion they discovered was quite shocking. 

Sheyla heard weird sounds from a nearby earth wall and poked it with her repeater. Her eyes light up murderously when she saw five paralyzed women being r*ped by ten goblins behind a disappearing illusionary wall that had probably been placed there recently so that they could take advantage of their captives in peace.