Core looked over his latest notifications and was happy. The two invaders gave him plenty of experience, a testament to their level and power. Compared to his own level he was a bit concerned about strong enemies invading his dungeon but luckily his defenders and his tactics pulled out the win. The big pudling gave his defenders a good amount of problems while the smaller one's indecisiveness signed it´s death-warrant.

He gained another item for the called a shield. Although it looked weak it did protect the big pudling against the attacks of his defenders. All the items that went into the feature were held by the invaders and used to attack his defenders. All his defenders used their natural attacks in a fight, maybe this was how invaders without those options fought.

The part that Core was most excited about was the fact that he finally unlocked the non-skeletal version of the pulling. Quickly he opened his defender creation tool and found the pudling on the list. He opened up a second screen and pulled up the skeletal pudling, Holding up both screens he compared the two defenders. The first notable thing was that the statistics no longer had the negative values behind them. This meant the defender was stronger than its counterpart but lost access to the resistances the undead version had to piercing and slashing damage In return the restriction on the Aquatic was lifted but Core still didn't have water in his dungeon. The last thing he noted was that living pudling had an option that said which made Core wonder when he would unlock this mystery feature.

Concerning more pressing matters at hand, he was now down one defender and his goblin was beaten and broken. The fact that the goblin managed to kill the lizard despite its wounds was a small miracle. It would need a good amount of time before its natural regeneration would heal the broken bones and refill its health points. Absorbing the two invaders awarded Core with just enough mana to complete his project but the thought as being down two defenders was a more pressing matter and after a quick moment, Core dismissed his goblin and went back to his Defender creation tool.

With his previous assessment still in place, Core selected the spider as his first option but selected the Shadow wolf as his second defender. Golbin was a good defender but with a free slot, Core wanted to observe the wolf in action for a while to get a feel for its combat abilities.

Core picked the spot right in front of the tunnels to spawn his new wolf defender. The lean skeletal frame of the wolf was supported by sturdy leg bone with the paws ending in jagged bony claws while razor-sharp teeth and fangs adorned the defender's strong maw. Core told the wolf to walk from one end of the tunnel to the other end in a casual stroll. Next up he ordered it to do it at a sprint. The speed seemed to be on par with the lizard at full speed so he made his two defenders have a race through the tunnel. As expected the sprinting wolf indeed slightly faster than the running lizard Core had them return to their starting places but this time the wolf was commanded to run full speed as well. The result was shocking as the wolf cleared distance in the tunnel in mere seconds. Core was very happy with his newest defender.

After Core concluded the speed trials and redirecting his defenders back to their location within the dungeon he opened up the two kill notifications he got from the fight. He did so because a difference between the two had caught his eye. While both of them were called pulling the small one was displayed as a level 3 and the large one was displayed as a level 1. The level of the big one was lower but he was worth more experience. Going over his own defenders he noted they were all considered as as well.

"Hey System, what the difference between these two names?"

When enough experience is gained a being can increase their level and gain more statistics.

After the initial stage monsters will advance into the stage. Monsters have a bigger increase in statistics then sentient beings.

After the initial stage sentient beings can advance into a stage. Each focusses on different statistics and can gain various Skills to support them.

"Hey System, can my defenders get a as well?"

Depending on the defender's species that is a possibility.

All your undead defenders are classified as a monster regardless of species.

Your pudling defender is classified as a sentient being.

Sentient beings also have access to to support their class.

Again the locked feature popped up, Core was really starting to dislike that he didn't know what this feature was. But like everything else that he couldn't control he'd deal with it once he could. For now, he had another issue to deal with.

Warning: An invading party has entered the dungeon!

With the last battle only an hour ago, Core wasn't too happy with another party inside his dungeon so soon. That changed quickly when he investigated the members of the party. Running along the wall of the cave he spotted two of those weak rats. How they classified as invaders still wasn't clear to Core but he assumed that everything that wasn't part of the dungeon was classified as an invader. Core didn't linger too long ón this thought as he took quick action against them by ordering the wolf to intercept them.

Wolf didn't miss a beat on receiving its master's orders and bolted through the dungeon tunnel to intercept the invader. At top speed, he lunged through the air and swiped at the first rat leaving long gashes in the side of the creature and swatted it aside. The second one was caught in a wolf's jaw where a quick bite ended its life. It took barely a minute before Core saw the victory pop-ups.

Rat Level 1 has been killed by Experience gained: 8. Current experience 123 / 125.

Dungeon Points gained: 1. Current Dungeon Points: 30. Progress gained: Understanding of archetype +20%.

Current % progress: 60 / 100. Undead archetype experience gained: 5.

Undead archetype current experience: 233 / 1.000. Skeletal Wolf experience gained: 5.

Skeletal Wolf current experience: 5 / 50. Rat Level 1 has been killed by Experience gained: 8. Current experience 131 / 125.

Dungeon Points gained: 1. Current Dungeon Points: 31. Progress gained: Understanding of archetype +20%.

Current % progress: 80 / 100. Undead archetype experience gained: 5.

Undead archetype current experience: 238 / 1.000. Skeletal Wolf experience gained: 5.

Skeletal Wolf current experience: 10 / 50. The dungeon has grown to level: 4. Core Health +100.

Core Mana capacity +25.

Dungeon points +10. Trap slots +0.

Defenders slots +0. New features have been unlocked: Monster den.

Armory.

Loot pool. Monster den door trigger has been added to the Assets tool.

Core had almost forgotten how close he was to reaching level 4. The level up had unlocked three new features and an asset. But with his new mana bonus from the level up Core could finally take expend his dungeon tunnels.

He quickly opened up his Dungeon layout tool and selected the expansion template he had constructed earlier and placed it onto his current dungeon He got a prompt if he was sure he wanted to add the layout to his dungeon and he quickly selected yes. Almost instantly the required mana for the expansion was drained from his mana pool. Normally he'd have to do the construction by mind but if he'd already made a template beforehand the Dungeon layout tool would do the work for him. The tool quickly and securely restructured the existing walls and tunnels to Core new specifications. It took around ten minutes before his dungeon settled into its newest form and Core was pleased.

Instead of just one choice between left and right, an invader would now have to make multiple of those choices to get to the end. With his future expansions already planned out, he'd only have to wait for more mana and then overlay those plays as well. Finally having completed his main goal Core took the time to look over the newly unlocked features for his dungeon.

Core looked at the newly unlocked features and picked the Loot pool first because the Asset was also tied to the first option and he wanted to save that for last and armory sounded boring. He selected the option in his mind but nothing happened. He selected it again but again nothing happened. He wondered why he'd unlocked something but couldn't select the option. So where else to go but to System with his question.

"Hey System, what's a Loot pool?"

When a monster is the wild is killed it can be harvested for materials. These materials can then be used to craft items.

When a sentient being is killed it can be looted of its items.

Defenders will now have a chance to leave behind one of those materials or items when killed. The mechanic adds value to the dungeon making it less likely that the Core will be drained and killed since it has an endless supply of defenders that can be killed for items while outside the killed creatures are born and now spawned.

So it wasn't something that Core could influence but it helped his survival in the end. It wasn't an issue for now but perhaps in the future when stronger invaders come to his dungeon would it be useful. Next up was the Armory feature.

Armory: Items dropped by invaders are collected into the Armory.

By spending mana a replica of the item can be made and equipped by sentient defenders. Items equipped by a defender are added to their Loot pool.

Check defenders for available equipment.

Core quickly opened his Defenders menu and selected the pudling. The previous locked feature was now replaced by the Armory option which he selected. His menu only held four options that could be equipped by the pudlings. While he had only absorbed three of those items it looked like the spear was listed as both one-handed and two-handed. Core would experiment with those in the future.

The final unlocked feature was indeed saved best for last. The addition of this would give him a lot to think about for the future development of his dungeon.

Monster den: Invaders that enter the Monster den must defeat all present defenders before the room can be unlocked.

Other defenders can not enter this room.

Traps can not be placed inside this room.

The Monster den can only be occupied by one species per den(subspecies can be mixed).

The cost of spawning defenders in the Monster den is reduced by 50% (does not apply to items from the Armory).

Another barrier for the invaders to cross on their way to his core. Core opened up his Dungeon layout and selected the Monster den. He turned the room into the tunnel before his core room but was greeted by the invalid red color. While the room would unlock if the defenders were defeated it seemed that the room only had one entrance. What good was a room that they didn't even need to enter? They might do it for the loot drops but that wasn't guaranteed if the room was optional. Core thought about the dilemma for a few minutes and reopened the level-up notification. There he found his answer on the very bottom of the notification, the Monster den door trigger.

Opening his Asset tool he found that instead of a physical trigger he could use the opening the monster den door as the trigger for a door. The door linked to a monster den also couldn't be forced open by an invading monster unless they killed the defenders inside the den. This new information gave Core some well-needed peace of mind. The den had a minimum required space of 5 by 5 but the cost of the room was only 100 mana, which was less than Core needed to dig out 25 spaces but that was without the defenders the room needed to function or a door it could trigger. While he gained more mana regeneration form leveling up Core wasn't happy he had to wait such a long time before he could use his Monster den.

A heavy thud was heard and the entire mountain the Core's dungeon was in seemed to shake from something that impacted the mountain.

And just as Core was finally happy about all his new progress a very ominous message was reported by the red box.

Warning: detected in close proximity to the dungeon! Spoiler: Dungeon map