***

  The creatures that came out of those gateways ranged from a small fruit fly to creatures completely made of shadow. While some were more dangerous than others, and some, like the fruit fly that had reached diamond, were not particularly fast or efficient at killing, they all had one thing in common—they were incredibly hard to kill. Some more than others, but all of them required specific artifacts combined with a unique set of skills to fully put down.

  While they varied quite a lot, over half of them were elementals. They were of all different kinds, but the four elements were represented the most, especially wind. They also had marching orders, and the elementals were the vanguard of this force, while the more unique creatures would take the side tunnels to clear them out while the vanguard moved into the main tunnels.

  There were a few reasons for this, one being that elementals could attack in wide areas and do so constantly without a break. The main reason, however, was that the largest of them could combine with other elementals—and that included monsters. So as the elementals moved forward, ETG continuously teleported appropriate monster elementals onto their path to be absorbed.

  Those elementals would still have their own consciousness and, later on, could split apart once again, but that was one of the reasons this tactic was used. Not only would this make the elementals even stronger, but it would also create the effect ETG needed—weakening the other dungeons' territories so he could go on the attack and push their territories back.

  In the territory of the 21 dungeons, the monsters were restless. There were also gateways made there, with real people now present to make plans so they could attack effectively when the surface armies reached ETG, allowing them to strike from both sides at the same time.

  The first sign of trouble for them was a breeze that was getting stronger as time went on. All of them looked around in confusion when they finally started to notice that the breeze had turned into what could be called a proper wind—and how strange it was to have something like this in underground tunnels.

  There was an obvious direction for that wind, and it was coming from the dungeon they were trying to destroy. Immediately, scouts were sent out, and they returned soon after, horror on their faces.

  This world had never before seen diamond-ranked elementals—only ETG had been able to produce them. So all of them were unprepared for the wind to get so strong that not only did it start to damage the dungeon’s reinforced walls, but small cuts also started to appear on the bodies of diamond ranks.

  Spells were cast and skills activated, reducing the incoming wind. They had not realized it yet, but the elemental attacking this particular tunnel was still miles away, and they would have to fight and kill off tens of thousands of platinum-ranked elementals before they could even reach the body of the diamond-ranked wind elemental.

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  Many of the other main tunnels were having similar experiences, as the majority of the elementals attacking were of the wind kind. They were cursing their luck, but they would soon come to learn that they were the lucky ones.

  The main tunnels that had the unfortunate luck were attacked by different kinds of elementals, like fire and sand, or worst of all—water. There was barely anything they could do against that, and soon, retreat orders were given.

  All of those dungeons and their masters soon learned why this was happening. As they were pushed back and tens of thousands of ETG monsters that entered their territory. They found their strength lacking, which ETG exploited ruthlessly, pushing back their territories and claiming them as his own. The more serious fighting was happening in the side tunnels—the smaller ones used to bring in more unique monsters.

  The monsters there found themselves unable to properly fight against their opponents, and their only options were to die or retreat. Yet, retreat did not come easily. A glowing fruit fly was quite slow in its pursuit, but it never stopped, and it particularly liked going through solid rock, which allowed it to get ahead of its prey thanks to the bendy nature of many of these tunnels.

  The magnitude of the attack crushed almost all resistance, and for days they continued to push forward, countering almost zero resistance. Yet the 21-dungeons and their masters weren’t stupid. Slowly, they learned what worked and what didn’t against their opponents, and soon different types of monsters started to appear, purposely made to try to fight these new types of enemies.

  At first, they achieved little, these new types of monsters barely doing anything else but dying. The masters of this dungeon were growing restless. Time continued to march forward, and instead of being ready to attack the dungeon as soon as the surface armies reached it, they were being pushed back, day after day, ever further from their goal.

  The surface armies of the four great powers had enjoyed an easy advance and quite a quick one. Yet all of them started to reach the invisible line ETG forces had drawn up, indicating how far they could reach without overextending themselves. It started slowly, with a few buried bombs that managed to kill quite a lot of platinums, but it soon escalated into not just killing traps but delaying ones.

  Huge areas were filled with devices that were triggered by the marching armies, covering the vast swath of landscape they were currently marching through in spiderwebs that even diamond ranks found hard to get past. Others received the same treatment with vines or even slime that hardened over time. Each one was dealt with quite fast, but it still took a day or two to get the armies back to marching.

  The amount of rare materials used just to delay those armies a day at a time would have easily cost some of the largest kingdoms in this world their entire year's income. Yet those tactics and traps were used liberally. Even when the armies deviated from their planned routes, they still found themselves delayed almost constantly.

  It didn’t take long for the armies to choose another tactic. They started to send out their diamond ranks to clear the way. This was exactly what ETG forces had waited for. Even better, those diamond ranks went at it alone, as clearing the way didn’t require multiple people. The first proper ambush happened two days after the tactic change.

  Diamond-ranked creatures and adventurers waited, hidden by skills and spells, while others were ready for a fast escape. Almost all of them received orders at the same time, and those who could do devastating damage attacked, killing many of their targets.

  Others, unfortunately, couldn't, as they were not positioned correctly. No matter if they attacked or not, no matter if they succeeded or not, all of them escaped just moments after their attacks.

  Dozens of diamond ranks were killed, and while that might not sound like many, there weren’t too many diamond ranks to begin with. Of course, the four great powers’ diamond ranks started to pursue, but only the fastest could keep up, and none seemed able to catch the escaping ambushers. That's when the second ambush happened.

  Another group, quite similar to the first one, had waited further away from the first ambush location. They had waited until the first ambushers passed by them, and when the pursuing diamond ranks rushed overhead, they attacked.

  They had a bit more time, allowing them to properly kill instead of just wound like in the first ambush. All pursuits stopped after that, and in just a short while, the attacking armies had lost nearly 100 diamond ranks.

  They continued after that more cautiously, but that also meant they advanced slower. All of those generals hated that fact, as that meant ETG had more time to build up. But if they rushed, they would lose more of their army, and they couldn’t afford that.