Deep within the Iron Nest, Deck 3.

  This was the core sector of the entire fortress, and also the area with the highest demon density.

  The Slayer had just cleared a wave of face-rushing Arachnotrons with his Dragon's Breath Shotgun, but more demons were pouring out from ventilation ducts in every direction.

  Especially those massive, dual-blade wielding "Cyber-Barons." These elite monsters were tanky; even with the new shotgun, it took two or three shots to put one down. And right now, there were twenty of them standing in front of the Slayer.

  In this situation, the simplest solution was—the BFG-9000.

  One shot, screen clear.

  The Slayer habitually reached for the Big Fucking Gun on his back.

  But his hand touched a cold barrel, and an energy indicator light that remained dim.

  Energy: 0%.

  The Slayer’s hand paused in mid-air.

  This weapon had been a "brick" ever since he drained it to nuke the Blood Sea Ancestor back in the 1st Layer. Although Singularity had been trying to recharge it via the cross-realm transmission line, the efficiency was pitifully low.

  "Great Warrior! Stop looking! It's really dead!"

  Singularity's voice crackled through the headset, accompanied by the background alarm of the Netherworld's generators overloading.

  "The cross-plane transmission loss is as high as 90%! Just to charge that one shot for you earlier, the Copper Pillar Hell almost froze over! If we keep charging it like this, the Netherworld will go bankrupt before you finish clearing the Abyss!"

  The Slayer frowned (under his visor).

  He didn't care if the Netherworld went bankrupt. What he cared about was the terrible feeling of holding a god-tier weapon he couldn't use.

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  BANG!

  Forced to switch tactics, he raised his shotgun and blasted a pouncing Imp into pieces.

  The moment the Imp exploded, the Slayer keenly caught a detail.

  Aside from the blue Soul Orbs (Health) and green Armor Shards dropping from the corpse, there was a faint, dark red wisp of malevolent energy rising from the body like smoke, quickly dissipating into the air.

  This energy was the foundational power of the Abyss plane. The source of demonic strength.

  The Slayer’s movements suddenly stopped.

  He let a Hell Hound bite onto his shin armor (it couldn't penetrate anyway).

  He looked down at the dissipating wisp of energy.

  Then he looked at the dead BFG in his hand.

  The core principle of the BFG is using Argent Energy to trigger a chain reaction. And the essence of Argent Energy is, simply put... refined Hell Energy.

  If that's the case.

  Why wait for "imported electricity" from the Netherworld?

  There is "local oil" everywhere here.

  The Slayer kicked the Hell Hound away.

  He turned his head to look at the micro-engineering drone that had been following him.

  He unslung the BFG from his back and shoved it right into the drone's camera lens.

  Then, he pointed at the roaring demons surrounding them and made a "SUCK" gesture.

  Although he didn't speak, Singularity instantly understood this imaginative tactical requirement.

  "You mean... sourcing locally? Use the demons' own energy to charge the BFG directly?"

  On the other side of the screen, Singularity froze for a second, then slapped his thigh hard, so excited he nearly jumped.

  "Genius! Absolute genius!"

  "Why didn't I think of that! This is 'War Sustaining War!' Since the BFG runs on energy, aren't these demons... just wandering, lively power banks?!"

  "I just need to add a filter to purify that raw energy..."

  Singularity immediately pulled up the BFG's schematics, his fingers flying across the screen.

  "Great Warrior! Give me five minutes! I'm going to whip up a 'Spirit Gathering Energy Siphon Mod' for your BFG!"

  "I'm going to combine the Eastern 'Star-Sucking Great Art' with Western 'Energy Siphon Technology'! Let them pay for the gun that kills them with their own lives!"

  The Slayer nodded with satisfaction.

  He placed the BFG on the ground, like he was waiting for dinner to be served.

  Then, he pulled out the Chainsaw.

  Since he had to wait five minutes, he might as well warm up in the primitive way.

  The surrounding demons were still blindly closing in. They didn't know that their fate was not just to be killed.

  But to become fuel for this world-ending weapon.

  Consumption vs. Endurance.

  The biggest weakness (ammo/energy limits) was about to be completely patched.

  Once the BFG achieved infinite endurance...

  It wouldn't be a battle anymore.

  It would be a steamroll.

  "Next Chapter: The Spirit Gathering Array Modification. Singularity micro-engraves a magic array onto the BFG. The Slayer discovers: As long as he kills fast enough, this gun will never stop."