Step by step, a large crowd of creatures marched through an underground tunnel. They were making their way through the Earth beneath City Z. This trek was not aimless, however. There was a set destination that these non-human entities sought to reach.

"How far are we now?"

"Not far. A few more minutes, and we should see it."

"I wonder if there's anything left. Maybe the reason Rover never came back is because he's been trashing the place."

"I think he's only six months old so that checks out. Puppies are easily distracted."

"I still can't believe one of our leaders is a frigging dog, man. What kind of crap is that?!"

"Hey! Shut yer yap! Have you SEEN what Rover can do? It's a literal killing machine. Even if all it did was tackle you, your bones would get crushed!"

"Nah, I'm made of tougher stuff than some oversized mutt. Hey, maybe if I put'em down, I'll get his spot as an executive."

"HA! If YOU make it, then we're all executives, too! Hell, we could just kill you and take your spot!"

"Alright! Shut up, idiots! We were told that, while slim, there IS a chance the Subterraneans defeated Rover. If that's true, then all your lip flapping is gonna give us away!"

"Bah, let'em come! We're almost there, anyway. They'll see us when we come out of the tunnel. Speaking of which, I see light up ahead!"

Sure enough, the exit was near. The crowd hastened its pace, swiftly finding what they were after. It was a MASSIVE cavern that contained an underground kingdom. Unfortunately, it seemed to be in pristine condition, meaning that there was work to be done.

"Alright, boys. Looks like Rover failed, and he failed HARD," The monster that led the crowd was the one to speak. He turned to face his allies as he spoke. "We can't just rush in there, no matter how strong we are. This is the Subterraneans' turf. We need to try and ambush them or otherwise we're-"

SCHLICK

THUD

...

...

...

No one was able to process what just happened. The leader of the crowd exploded. Specifically, it was his chest. There was a large opening that showed the shattered bones and shredded meat within him. Through this gaping hole, you could see the ground where his corpse lay. Embedded in the rocky terrain was a perfectly smooth metal ball. However, this sphere wasn't the same size as the wound it created. Likely, it was the destructive impact that resulted in the devastation.

But...where did it come from? There was no one in the distance. Everyone had been looking in that direction, and no one saw a sniper of some sort. It definitely didn't come from behind, as there were far too many bodies that would've acted like meatshields. So, if not from the front or back, where did-

CRASH

The crowd had been too shocked to notice a noise. It was heavy and mechanical, a grinding sound that grew in volume with each passing second. The commotion that was just heard was the source revealing itself.

Something had arrived from above, WAY above. It fell from the top of the cavern and landed on the centermost structure, a massive ceremonial temple. This thing was a giant mech that had tunneled down here from the surface. It possessed myriad weapons, features, and gadgets.

"I wasn't mistaken, Silver Fang. My drones detected noise coming from beneath us. I've spotted a horde of monsters that appear to be returning from elsewhere. My immediate surroundings indicate a civilization. Maybe it's a monster colony?" A deep male voice spoke from the robot. It wasn't even addressing the creatures, but someone else named-

"S...Silver Fang?..." A monster whispered as their eyes widened. "That...That's an S-Class hero! I'm sure of it!" They exclaimed.

"But...But if that thing is talking to Silver Fang...then...then it's...M...M...M..." A second monster stuttered.

"Metal Knight," The mech said, now focusing on the crowd. "I'm pleased to see that beings like you are aware of my reputation," He admitted.

Without any commands being issued or a collective agreement being reached, the crowd turned around and booked it. METAL KNIGHT?! OF ALL PEOPLE?! THAT HERO WAS A WALKING SLAUGHTERHOUSE! NO ONE HERE COULD WITHSTAND HIS FIREPOWER, AND THEY SURE AS SHIT COULDN'T FIGHT-

CRASH

"Apologies," Metal Knight spoke again, this time from a second mech that arrived to block the monsters' escape route. "I'm afraid you're not going anywhere. If I were a different hero, I might consider interrogating you. But given my objective is extermination, that'd be pointless." He told them.

"W-WAIT! PLEASE! WE CAN SHARE A LOT! VALUABLE INTEL! YOU'LL WANT TO-"

SCHLICK

SCHLICK

SCHLICK

SCHLICK

SCHLICK

...Five...Five monsters...dead...instantaneously...it...was the same as before...a metal sphere...it pierced them all...it was fired from a shoulder-mounted gun on the mech...

Immediately after, the underground was filled with screams, blood spatters, flying bone fragments, and a symphony of weapons firing. Metal Knight would not take any chances. Was the impossibly powerful entity among this riff-raff? No. But killing a group of hostile entities was beneficial regardless. Plus, there was this newly discovered civilization to explore. Hopefully, the answers he and his colleague sought will be found here.

Elsewhere

Gracefully, like a pod of whales surfacing to breathe, the Subterraneans emerged from the underground. The total amount of time it took for them to do so was somewhere between thirty and forty-five minutes. That was impressive since they not only carved through the Earth but also through a bunch of metal pipes carrying water or gas and strange cables that conducted electricity. None of them were sure why those things were there or what purpose they served, but it was unimportant. Now that the Subterraneans were free, they could begin their journey proper!

"Well done, men!" Xiomara exclaimed with a proud and happy expression. The Subterraneans bowed their heads in appreciation. "Now, given the position of the sun, I'd say we're currently facing toward East. We need to head South if we're to find Boros' ship. So, keep close, watch for any human life, and be ready to dive into the ground at a moment's notice. If we keep to the wilderness, we should be fine, but ALWAYS remain vigilant!" She instructed.

"Yes, your highness!" The Subterraneans replied.

With nothing left in their way, the queen and her people headed into the vast unknown of the surface world. At a steady pace, they should reach the ship in an hour or so, maybe quicker if they switch to a jog or sprint. Hopefully, Saitama and the others weren't too far along in their training yet.

Meanwhile

Saitama was lying on his back on the ramp of Boros' ship. Near the bottom, he had a perfect viewing angle of the sky above and a nice balance between sunlight and shade. His arms were behind his head, and there was a smile on his face. Honestly, this was going to need to become a regular thing.

"Saitama!"

That was the friendly voice of the bipedal man-eater, otherwise known as Groribas. He strutted from the ship toward the bald hero with all three mouths expressing excitement.

"Hey, Groribas," Saitama greeted him in return. When the plant man was close enough, he looked down at Saitama, allowing him to keep his head and neck in a comfortable position.

"Where's blondie?" Groribas asked, briefly scanning the nearby environment. "Did you have him go get you a snack or something?" He guessed.

"Nah, that'd be mean, even if I tried to come up with some reasoning for how it will help improve him," Saitama answered, followed by a sigh. "To tell ya the truth, Groribas, I'm not sure how to handle this. Genos really thinks I can help him get stronger, but, like, the dude's a gun with a face. Anything I could offer wouldn't improve him in the slightest." He said.

"Yeah, I get ya," Groribas replied while folding his arms. "Just so I know, though, what is blondie doing right now, then?" He inquired.

"I told him that there will be times when he's forced to react while moving at top speed. If he comes across an opponent that outclasses him in that department, Genos would just have to stand there and take punches or waste energy trying to catch the guy. So, I told him to do what Boros did yesterday and fly around as fast as he could while avoiding obstacles." Saitama informed him.

For a second, Groribas once again looked around at the empty wastes surrounding the ship.

"Huh, he'll be flying for a while, then..." Groribas commented before focusing back on Saitama. "Well, if you'd like, I could help you come up with stuff to put blondie through, so he won't think you're just improvising." He offered.

"Seriosuly?!" Saitama questioned with widened eyes. "Groribas! Dude! You're a life saver!" He exclaimed.

"Nah, I'm just that good of a guy," Groribas humbly responded with a stupid grin on his face. "However, in exchange for my expertise on how to train metal boy, I'd like to make a request." He said.

"Shoot." Saitama invited.

"Our mistress has had a lot to deal with lately. There was the prophecy, then realizing she can't fight you as an equal, followed by the Association making things complicated, and then your home burned down on top of it all. I think Lady Boros needs to get away for a bit. A nice, normal, relaxing distraction from all the hullabaloo that's happened." Groribas stated.

"You know, I agree. Boros has gone up and down with her stress and emotions. She would benefit from a total reset." Saitama replied.

"Exactly! See? Great minds think alike," Groribas carried on. "Anyway, I think the best idea would be an island getaway. Or, if we can't manage that, an isolated beach somewhere. That way, we can kill two birds with one stone. There'd be plenty of training opportunities and ways to unwind. Spend half the day working out and the rest of it relaxing by a bonfire or chilling in a nice, cozy lodging house. We spend a week there, maybe two, and I'm confident our mistress will be better than ever before." He described.

"Wow, Groribas, you know a lot about a vacation on the coast," Saitama noted.

"There are all kinds of worlds in the universe, Saitama. You'd be surprised how many species decide to convert their native planets into intergalactic hotspots. You've got winter wonderlands, tropical dreams, one-stop shopping destinations, and whatever else you can think of! Keeping up the crew's morale is important, so we made a few stops here and there during our conquest." Groribas explained.

"Oh, yeah, you have a crew," Saitama remembered. "It's weird. I've not really seen anyone other than you guys and Boros." He realized.

"That's no surprise. They're basically background characters. No real point in trying to make them more relevant than we need to." Groribas said.

"...What?" Saitama questioned with a quizzical expression. It took him a moment to process what he heard.

"I said they're busy all the time. Maintaining a warship is hard work." Groribas repeated.

"...Huh...I must've misheard you..." Saitama muttered before letting it slide. "Anyway, so, are we set for a beach or island trip, then?" He asked, just to be sure.

"Yup! We're working out the details now. I'll keep you posted when we've got more figured out." Groribas answered.

"Sounds good," Saitama responded. With that, the conversation was over, and Groribas returned to the ship.

In Boros' Throne Room

BOOMBOOMBOOMBOOMBOOMBOOMBOOMBOOMBOOMBOOMBOOM

The inexplicably vast throne room resembled the night sky during a fireworks display. There were flashes of light here, there, and everywhere. If someone walked in here, they'd likely have a seizure. If they didn't, such vibrancy and intense strobing could give them epilepsy.

Bors and her puppy, who still needed a name, were like two wild animals who'd been injected with a life-threatening amount of adrenaline and psychedelic substances. With absolute abandon for the condition of the throne room and its seemingly infinite number of pillars, these two monstrous beings unleashed their full power. Boros let fly a constant spread of glowing purple projectiles as though it were the world's deadliest blanket. The puppy ejected massive balls of energy that plowed through the scenery like a rocket-powered bowling ball hitting pins made of sugar glass.

All the while, Boros was laughing like a mad woman with the purest smile on her face. The puppy's tail was wagging so fiercely that it generated winds not dissimilar from those of a rising storm. Together, this duo was darting all over the place while reveling in their destruction. Was this training? Was it playtime? Truthfully, I don't know if anyone could make sense of-

"LADY BOROS!"

Instantly, everything became still. The booming voice from one of her elites froze both Boros and her puppy. Its commanding quality was due to multiple voices speaking in unison. Who else could it be other than the shapeshifting wonder of the universe?

"...Hey...Melzargard..." Boros turned to greet her elite with a nervous grin.

In reply, Melzargard merely stared at his mistress with folded arms and ten pairs of stern glares.

"...Okay, listen," Boros began as she held up her hands. "Scold me all you want. Leave my baby out of this." She told him.

"Your baby, mistress?" "Your affection for this creature is developing at a surprising rate." Two of Melzargard's heads said.

"LOOK AT HIM!" Boros shouted while pointing at her puppy. During this, the puppy was sitting down and not moving to avoid incurring Melzargard's disappointment. "He's just a big sweetie! He'd never do anything wrong on purpose!" She reasoned.

"The sea of rubble in this room suggest otherwise," One of Melzargard's heads argued.

"Hey! I said this is on me!" Boros insisted, pointing at herself. "It started simple. I was teaching him basic commands. And, like the brilliant good boy he is, he understood each assignment right away. Sit. Stay. Roll over. Lie down. And finally, shake." She informed him.

...

...

...

"Mistress," After a brief pause to process that information, the same head from before spoke again. "If you're not trying to deceive me, how did the oldest commands in the universe lead to a light show?" He asked.

"Pfft...you...you act like it isn't obvious..." Boros scoffed while looking away from him.

"M'lady." The same head said sternly.

"..." Boros hesitated. She was trying to make it sound good in her head, but no arrangement of words was working. "Okay, so, maybe when I asked him to shake, it allowed me to get a good look at the muscles in his legs-"

"Mistress, did you arm wrestle your puppy?" The same head cut her off, assuming that was the direction.

"What? No. That'd be silly," Boros denied the accusation. "I just thought that with such great muscles, he'd be able to run REALLY fast. So, we raced around the entire throne room. However, with four strong legs and me running on foot as well, he managed to get ahead of me. He is also SUPER good at taking turns and not losing any of that speed. I felt that it wouldn't be fair to him if I held back, so I used my power to start flying. When he saw me do that, he evened the playing field by taking a shot to slow or knock me down. The rest...well...you saw it..." She explained, getting sheepish by the end.

The five heads of Melzargard all looked at their mistress with disbelief. There was a tense air in the room for nearly a minute. Neither Boros nor her puppy dared to move an inch or make any noise.

CLAP

"Very well," The same head continued speaking as Melzargard clapped his hands. "It would appear that there are two people on this ship who need to be trained." He determined.

"What the, HEY!" Boros reacted with a glare and a pout. "Melzargard, we just got a little rowdy. There's no sense in making a big deal out of this!" She objected.

"Your displeasure is acknowledged," The same head assured her, worsening the pout. "From now on, I will assist you with the puppy's training while simultaneously helping you with impulse control." He decided.

"WHAT?!" Boros yelled before storming over to him. "Listen here, Melzargard, I am ALWAYS in control! If I weren't, you and the rest of the crew would be a pile of ashes by now." She reminded him.

"That was because of your armor and your overwhelming boredom, mistress." "Now, you only wear your limiter as ceremonial attire and are regaining your emotions." "If we don't do this now, then you'll probably explode like a bomb when someone does something harmless like bump into as you walk." "That is bad." The other four heads of Melzargard told her.

"BAH! That's ridiculous! I wouldn't just lose control and blow up!" Boros protested.

In reaction, Melzargard's heads looked at the previously mentioned sea of rubble. The longer they stared, the more Boros' angry demeanor crumbled.

"...ALRIGHT! STOP LOOKING AT IT!" Boros ordered with a noticeable blush on her face. "Fine! If it will get you off my back, I will accept your aid with my baby's training." She permitted.

"And your emotional control," The one head added.

"..." Boros crossed her arms and looked away once more. "...Maybe..." She grumbled.

With a collective sigh and headshake, Melzargard split into his five selves. Normally, any damage done to the ship would be automatically repaired, but he felt it best if these two sentient hurricanes did that manually. The puppy was more than happy to follow instructions issued by Melzargard. As for Boros, she kept looking over her shoulder as she could feel the analytical stares from her elite. Wasn't she supposed to be in charge around here?!