Digging a Tunnel… Again

Deep within the Black Sea, the Regal Fiend Tower's fragments were scattered on the seabed, and more were sinking down. 

The tower, which had never broken apart despite its broken state, was now starting to crumble piece by piece. 

The tower's bottom was penetrated deep within the seabed, and it goes all the way into a spacious underground field. This entire field was filled with complex runes. 

The tower covered 95% of the runic field, and it was over 2000 meters in size. 

At this moment, the hundred-meter-tall black gate of the Regal Fiend Tower was creek opened after a very long time, revealing Ace and Eva holding each other hands. 

Ace looked at outside, and his eyes landed on the runes engraved on the floor outside. 

"This formation is hundreds of times larger than the one I used to come here. I wonder why and who made this secret realm and then abandoned it." Ace wondered out loud.