Mard Geer Tartaros, the founder of the Tartaros guild and it's sub-leader. The reason why he was the sub-leader is that even though he founded the guild was for E.N.D to lead it.

Well, that's what Ben heard from the guy himself after they met and talked because Ben wanted to get some information first. He found Mard Geer inside a huge castle located in this massive cube. The guy is sitting on his throne arrogantly even though he knew Ben defeated 6 out of the Nine Demon Gates.

It will be 7 actually because Silver was defeated when Ben killed Keyes. Silver was actually a corpse that Keyes revived with his necromancy. Ben knew this from Wendy who called him while he was on his way to find Mard Geer.

The surprising thing was that Silver is Gray's deceased father. Though he told Gray who had come to the cube sometime ago with Elfman, Juvia and Cana that he was Deliora in Silver's body. It's when Keyes's spell wore off that he told Gray the truth and even passed his Ice Devil Slayer Magic to him.

"You guys are really annoying, aren't you? This Mard Geer doesn't know how you keep coming here in a short amount of time, but Mard Geer won't let it happen anymore." Mard Geer angrily said.

"Heh, you talk as if you can stop us from coming here. Let me tell you, it's impossible because everyone in our guild knows where this place is. You can't prevent us from coming here. It's too late." Ben said while looking at Mard Geer with a smirk.

Mard Geer suddenly felt something and got up from his throne. He looked far beyond Ben as if he is looking outside the cube.

"Have you realized it now? You were targeting us before, but now, you have become our targets." Ben said.

Mard Geer frowned and Ben continued, "You are messing with the wrong man, wrong people, wrong guild. You shouldn't mess with Fairy Tail."

BOOM*

A super loud explosion is heard by everyone alive in the cube. They can also feel a strong tremor that made most of them fall on the floor. Mard Geer clicked his tongue because he never considered this scenario.

The massive explosion came outside the cube. It came from a massive shot fired by a big airship. The airship was white with gold accents and big gold marks of Fairy Tail.

It was Fairy Tail's airship that fired the super strong attack with it's magic cannon. The cannon looked small and it is located in the middle. Even if it was smaller than the ones that Grimoire Heart and Phantom Lord used, it was more powerful than both.

Ben built the cannon himself and he used knowledge from his past life as an elite soldier who knew a lot about weapons along with his magic knowledge. The result was this super powerful magic cannon that can destroy a mountain. The only cannon that has the potential to be stronger than this in Ishgar is Etherion.

With the cannon's power, it can create a large hole in the massive and strong cube. This was the reason Mard Geer looked pissed. This cube was part of his power and it was made to be very strong and indestructible.

But Ben has destroyed a lot of his parts and now Fairy Tail's airship did a lot more damage too. Mard Geer really wanted to attack the airship right now, but he can't leave because of the man in front of him. Even the arrogant Mard Geer knew that Ben wasn't a opponent he can face while thinking about other things.

So he focused on Ben again, but he did it a little too late because Ben made a move while he was distracted. Ben didn't attack Mard Geer though. He simply took something in Mard Geer's hand. It's a book that piqued Ben's interest since he arrived here.

This book was the reason Ben bothered to talk to Mard Geer for a rather long time right now. He just wanted to steal it, but he didn't know if Mard Geer has a monstrous reaction time or not. So he played it safe and distracted the demon first.

"The book of Zeref's strongest demon, E.N.D, huh? This must be an interesting book. I'll take it." Ben said with a grin before storing the book in his spatial storage.

Mard Geer looked enraged right and he shouts. "WHERE'S THE BOOK? WHERE'S E.N.D'S BOOK?"

Ben just smirked and said. "You want it? Defeat me and you will get it back, Mard Geer!"

The enraged Mard Geer's body suddenly started to change into his Etherious form. Wings come out of his back, his fingers turn into claws, horns grow on his head and his appearance changed. His current appearance is the coolest demon form that Ben had ever seen.

"Damn, man, you should just stay in your demon form all the time. Your human form made me want to punch you in the face, but this appearance looks good." Ben said, impressed.

"SHUT YOUR MOUTH, PUNY HUMAN! JUST GIVE ME THE BOOK OF E.N.D BACK!" Mard Geer angrily shouted while dashing at Ben.

Mard Geer moved very fast and as he moved, a lot of big thorny vines came out of the floor. The thorny vines are moving towards Ben a lot faster than Mard Geer. Ben just stood there calmly and looks at the attacks that look slow to him.

"I was hoping to see a lot more from you, Underworld King. It seems you're weaker than dragons, truly disappointing." Ben said before snapping his fingers.

After Ben snapped his finger, dark red solar energy appeared on the floor around him. The dark red solar energy suddenly spun and became bigger. A dark red flaming tornado suddenly appeared and it moved towards the incoming thorny vines.

The attacks clash and Ben's dark red solar energy tornado broke through the vines quite easily. It burned the vines and made them explode. These thorny vines would explode if Ben let them hit him, it was nearly identical to Azuma's Great Tree Arc spell.

Mard Geer was surprised that his attack was destroyed so easily by Ben's magic. He is just like the other guild members who believe Curses are superior to magic. That's why they were surprised Ben destroyed their Curses with ease.

Ben's dark red solar tornado hit Mard Geer and it grinds the demon inside it while moving around the castle, destroying a lot of it's parts. When Ben stopped the spell, the castle looked as if it had been abandoned. Mard Geer was kneeling after receiving a lot of injuries.

"Whoa, you defended yourself better than I thought. Only receiving minor injuries from that means you are very durable." Ben said, impressed.

Even if Mard Geer was injured, they were all on the surface. Ben knew he didn't receive any fatal injuries despite looking miserable right now. This guy was doing well when it came to defense and Ben is impressed.

Sure, Ben wasn't giving his all with that attack. It could be considered a warm up to test Mard Geer's abilities. It was strong enough to kill normal Etherious and injure strong demons like the Nine Demon Gates significantly.

This shows that Mard Geer truly deserves his title as the Underworld King and the leader of the dark guild Tartaros. Even if he was impressed though, Ben wasn't excited because Mard Geer was weaker than the dragons he fought last month. Those dragons wouldn't take damage from this kind of attack.

"It seems Zeref didn't create you well enough. For someone that lived in the era of dragons, he couldn't even make a demon that was as strong as a dragon. Oh wait! I still think you're as strong as a baby dragon." Ben said with a smirk.

Ben's mockery angered Mard Geer even more because he just mocked his creator. His goal as a Etherious is to kill Zeref, but he won't allow anyone to insult his creator. So Mard Geer attacked Ben while yelling angrily.

Ben faced Mard Geer's attacks head on while continuing to taunt the demon. This is one of Ben's bad habits. He likes to mess with his opponent's minds. But this is also a good strategy because somehow it always works.

Mira once said that he can make people angry just by looking at his face. Others even said that he is the annoying looking friend that always cares for them, so they can't leave him. That's why he doesn't need a lot of effort to play with his opponent's minds, just like now.

Ben smirked while he evaded Mard Geer's attacks. "It seems this isn't enough to make him come out. Hmm, I'll step my game up, then."