Capítulo 173: Chapter 173 - Location

Already came to the elf Kingdom. As you can tell, using his full power he was able to enter the elf Kingdom without any problem. Those barriers could protect the kingdom from Monster and other fighters. But if the monster has already reached the limit or even the fighter they can easily break through. Because the World Tower also did not guarantee that you are very well able to protect your kingdom or your territory from everyone. 

The barrier also has a limit so you can say that Alex is easily able to break the limit. Even though he went without using his power decided to enter the territory, unable to do that because he was feeling a prevention force that prevented him from entering the territory but after using his full power he easily broke that and entered the elf territory.