Adam used the Ethereal Recovery Skill for a few hours, then went on to stretching and relaxing his body that was aching quite a lot after being strained and pushed past its limits.

The Goblin Beasts that were surrounding the Core Part of the Goblin Beast City were all watching Adam and were both afraid and hateful towards him as they stood there unable to approach or attack him.

Adam taunted them and launched a few Dual Slashes towards them, wanting to test out whether he could attack them from the Core Part of the Goblin Beast City and was pleased to find that he could.

However, he didn't continue doing so to reserve his energy for battling against the other 3 Goblin King Beasts that were left for him to face, as he could always take down the rest of the goblin beasts afterwards.

Adam wasn't planning on sparing a single one of them and was curious and interested to see what he could find inside the castle and what other mysteries the floor held, so he decided to check the body of the Beast Goblin King, or what was left of it.

It had been completely destroyed and all that was left was green blood splatters and pieces of the beast's body all over the place, and unfortunately, Adam couldn't find anything that was interesting or valuable, which he found unusual.

Most of the other beasts had a valuable weapon or an item with some sort of value, and yet he didn't find anything of value or salvage anything from the Goblin Beast King.

However, thinking about it, it was unusual that despite Adam causing a large commotion and being in their territory, the other Goblin Kings didn't leave their towers, which hinted to Adam that they each held something valuable in their towers.

The Goblin Kings seemed to only be able to engage Adam in combat if he entered their towers or attacked first, which was good for him as it allowed him to prepare and make sure that he only had to face one of those beasts at once.

"I wonder what it could be that each of these Goblin Kings are protecting and whether or not they are linked. Could it have something to do with their control over the goblins or their power?" mumbled Adam to himself as he headed towards the Beast Goblin King's tower.

Adam was praying that whatever the Beast Goblin King was protecting wasn't lost or destroyed as he used his Burst Movement Skill that would allow him to kind of fly to reach the top of the tower.

The wall on the side of the top of the tower had been smashed apart after Adam had been launched through it and the Beast Goblin King also broke through it, which was convenient for Adam to enter the tower.

Landing inside, the top of the tower was large and connected to a closed-off room in the castle and was pretty large but quite empty.

Other than a small chest, there was only a bed formed from straw and grass, but that was to be expected from the Beast Goblin King that was less of a humanoid and smart creature than the other goblin beasts.

Adam was a bit suspicious of the chest and also found that he wasn't able to sense or gauge what was inside using his spiritual sense, but since he had nothing else to search inside, he didn't hesitate and went to open it.

He didn't know what to expect, but he was hoping that there was some sort of valuable or useful treasure that would either give him a power boost or help him when he explored the castle after taking down the other 3 Goblin Kings.

Adam had a rough idea of what the other 3 Goblin Kings would be like and was most interested in exploring the room of the Mage Goblin King that would most likely be filled with interesting items, but for the time being, was carefully opening the chest.

There weren't any locks and the chest was small, and similarly to the castle and the towers themselves, they seemed to be able to stop one's spiritual sense from penetrating through and peering inside, making Adam even more curious to find out what it is.

Without any traps, locks or dangers, Adma opened up the chest, however as soon as he did, he was soon disappointed to find that there was only one item inside.

And that item seemed to be a useless black stone that had no use.

Adam couldn't sense any energy inside it and other than seemingly being a very durable material, he couldn't find anything else that was useful or valuable about it.

Slightly disappointed, Adam looked around for a short while longer and smashed apart some of the floor and the walls with his powerful and tempered fists, hoping to find something hidden.

However he didn't find anything and it seemed as though the Beast Goblin King was the fastest, strongest and most dangerous beast that Adam had faced, but didn't have any valuable possessions anyway.

Knowing how unpredictable the system was and not confirming that the black stone that he found was completely useless, Adam placed it in his inventory before climbing down the tower.

There were many things going through Adam's mind as he went down the stairs of the tower, but he had no complaints with the position he was currently in and he began planning what he was going to do next.

Defeating the Goblin Kings was obvious, but there were still thousands of other goblin beasts and many unanswered questions that he had.

Adam trusted his instincts and with that black stone that he had, he felt that there was more to it, but until he defeated the other Goblin Kings and investigated some more, he couldn't confirm any of the ideas that he had.

"Well then, there's no need to delay it any longer. I wonder what my luck will be like this time and what Goblin King I will face" said Adam as he headed towards another one of the four towers.