NOTE: Back with another installment! And a chapter that's more about Serena rather than our main duo. Next couple of chapters will obviously center around them more and the story.

Currently Yuji does NOT have Leonidas' character or Ability card. He will gain those as the story progresses.

Funny enough. Neither Vladitor nor Hydranoid will be the first Darkus Bakugan Yuji and Leonidas will face.

Marduk's backstory might be changed a bit, because of how little it was explained. The partner that betrayed him will still exist, because that is essential.

You will be seeing what G-Power Leonidas will have next chapter. And this chapter does explain how the 'upgrade' mechanic works.

I'm also happy that you guys like Serena. I enjoy writing her as much as I do Yuji.

Review and Enjoy!

Chapter 4: Little Siblings Clash! Serena vs Akira!

The chirping of birds could be heard outside of the window of the small bedroom. Within the room was Yuji, who was snoring loudly with a dreamy smile on his face. Drool dripped over his pillow from his open mouth. "Go…go…Leonidas…" Yuji muttered in his sleep.

His partner, who was wide awake, could only sweat drop at Yuji's delusions. The Haos Bakugan gazed out of the window, watching the morning sunlight illuminate the room. "He's been asleep for so long? When will he awaken?" The Bakugan pondered.

CLICK!

Leonidas turned around to see the door to Yuji's room open up, the perpetrator was none other than his partner's little sister. The little girl was dressed in a white nightgown, and pink bunny slippers. Her light blue orbs noticed that he was staring at her, making the girl let out a small yelp.

Any idea of messing with her brother was forgotten the moment she saw Leonidas. Quietly scurrying over to the desk, Serena brought her face directly up to Leonidas. The poor Bakugan lightly flinched from the girl's close proximity. "Oh…! You really can open up on your own!"

"..."

Serena tilted her head. "Are you still not talking to me?"

"..."

The little sister pouted. "Come on…! I'm way more fun than Yuji! He likes to watch boring old soap operas with mom!"

"Soap Operas?" Leonidas had no idea what that was.

Serena's mood continued to dip as Leonidas sat there staring at her. Yuji had told her that he could speak like Drago, but he had never said anything to her. "Are you just dumb?"

A cartoonish tick mark appeared on Leonidas' head from the insulting comment. He reverted to ball form to hopefully tune out the girl until Yuji woke up.

Serena was equally as irritated. "Tsk! You're just like Yuji! No fun at all!" Turning to look at her peacefully sleeping brother, Serena's face twisted into a sadistic smirk. She backs up away from Yuji's bed before sprinting forward and jumps into the air above his bed.

"WAKE UP!"

"GAAAHHH! SERENA!"

Yuji bit into his sandwich as he entered the park. Leonidas was resting on his shoulder, since his partner refused to sit in the case with the rest of his Bakugan. Running ahead in front of them was Serena, the girl happily rushing to the park.

"C'mon, Yuji! We have practice to get in!" Serena complained.

"Yeah, yeah! Just don't run too far ahead!" Yuji warned. The boy had enough time to settle his mind to think about all the events that had transpired yesterday. His life had changed widely in such a short amount of time.

"But what if there's someone waiting to battle? We might miss them!" Serena pouted.

"We still have two days before the tournament starts, Serena. We have more than enough time to battle," Yuji reminded her. He wanted to battle with Leonidas to see how powerful his partner is but rushing things wouldn't help anything.

"Alright! But I'm not waiting for you!" Serena ran into the park before Yuji could say anything back.

"Ugh! Where does she get all of this energy from?" Yuji complained.

Leonidas hummed from his shoulder. "She is a strange one. I cannot understand how she thinks." The Bakugan thought back to the earlier events this morning.

Yuji glanced down at him. "Serena's always been a bit of a wild card. She acts before she thinks and is always quick to fire off a smart comment. Though, she always enjoys trying something new, believing that trying new things is the best way to have fun."

"That 'fun' thing again. Does Serena also gain a burst of energy like how you described?" Leonidas asked.

Yuji scratched his head. "Well…she is definitely a dumb ball of energy."

"Ah, so she is the dumb one. I can agree with that," Leonidas said.

"Wait, what are you-"

"AHHHHH!"

Both partners jumped at the scream that erupted from the park. Recognizing one of those shouts as Serena's, Yuji sprinted towards the park to save his sister. When he arrived, he found two things.

First, his sister was in no danger whatsoever.

Two, she was in a shouting match with Shuji's little brother Akira.

Something in the back of his head was telling him that this was going to be a long day.

"Why did you bump into me, shorty!" Serena shouted.

"Me!? You ran into me, because you're incapable of watching where you're going!" Akira shouted back.

"You're too short for me to see! Not my fault!" Serena crossed her arms, smirked. She took satisfaction at the steam rising from the boy's head.

"You think you're so smart, huh!?"

"Yes, I do believe I possess adequate intelligence."

"Then how about a brawl!? I'll show you that you're messing with the wrong brawler!" Akira challenged. Then he smirked mockingly. "Oh wait. You don't have any cards do you? You only have three useless Bakugan!" He laughed triumphantly until Serena reached into her bag and pulled out six cards.

"You were saying?" She smirked.

The boy blushed in embarrassment, seeing that Serena just made him look like a fool once again. Quickly thinking of some way to get the situation back into his favor, Akira pulled out a Gate Card. "Fine! You won't be able to beat me! I've got more experience than you!"

"That's exactly what your brother said before Yuji kicked his tail!" Serena smirked with pride and confidence. She pulled out her own Gate Card.

Yuji, who was watching from the sidelines this entire time, quickly pulled out his own Gate Card before the two got started.

Flipping the cards, a bright light began to emit from them both. Time seemed to slow down as the three brawlers and Bakugan were being teleported to another dimension.

"FIELD OPEN!"

Yuji released a breath of relief at seeing that he managed to make it in time. There was a bit of shaking on his shoulder, alerting him to turn to Leonidas. "Hm? You okay, Leonidas?"

The Bakugan turned to him. "This place…where are we?"

"Ah, this is a pocket dimension. It's where all of our battles will be taking place," Yuji explained.

"This dimension…it feels like Vestroia," Leonidas said.

"Vestroia? What's that?" Yuji had no idea what that was. Though, he does remember Leonidas mentioning it when they first met.

"It's the world that all Bakugan originate from," Leonidas answered. After saying that, there was something nagging at the back of his head. "But…how do I know that…?"

"What do you mean? Aren't you from Vestroia, Leonidas?" Yuji looked concerned.

Leonidas didn't answer immediately as if he didn't know the answer himself. "...Yes, I believe so."

Yuji frowned; something was obviously bugging his partner, but there wasn't much time to focus on that. He'll just ask him once they get home. Right now, he needs to focus on Serena. The newbie brawler turned his attention back to his sister and Akira.

"GATE CARD, SET!" Both brawlers shouted. Tossing down their Gate Cards, the cards expanded once they touched the ground.

"Since I'm such a gentleman, I'll let you go first," Akira said.

"And as a proper lady, I'll be sure to dish out an ideal punishment for you," Serena smiled. She grabbed a Bakugan from her bag. "Bakugan, brawl!" She tossed it towards her own Gate Card. "Bakugan, stand!"

Rising from the bright blue light was an Aquos Saurus. The Bakugan roared loudly in anticipation for battle.

Aquos Saurus: 180 G!

Serena danced with glee in her spot. "Hi, Saurus! It's nice to finally see you!" She shouted, happily.

Yuji sweat dropped from Serena's behavior. His sister could find almost anything cute when she wanted to.

Akira on the other hand wanted to puke, he wanted nothing more than to shut this noisy girl up for good. Grabbing his own Bakugan, Akira was ready to battle. "Bakugan, brawl!" He sent the creature flying towards Serena's Saurus. "Bakugan, stand!"

Emerging from the brown energy ring was a Subterra version of Juggernoid. The large tortoise stomped its feet before roaring at Saurus.

Subterra Juggernoid: 200 G!

Yuji was shocked by the G-Power that Akira's Juggernoid had. "200? But, Shuji's Juggernoid only had 170 G." His mind drifted back to something that Alice had explained to them before they left the store.

"Oh! Before I forget to tell you, a Bakugan's G-power can change depending on how much they battle. Every Bakugan has a limit, so don't expect one of your Bakugan to suddenly hit 600 Gs just from repeated battles."

"So, that's what Alice meant…" Yuji nodded his head. He looked over at Leonidas to see his partner focusing intensely at the battle in front of him. "I wonder if Leonidas has a limit."

Back with Serena, she was frowning deeply at Akira's Juggernoid being stronger. "Great…now I gotta deal with this."

Akira lifted up an Ability Card. "Ability activate!"

Subterra Juggernoid: 200 G to 220 G!

Serena gritted her teeth at seeing his Juggernoid's power increase by 20 Gs.

"End it Juggernoid!" Akira commanded.

"Not so fast!" Serena knew she needed to act immediately. "Ability activate! Saurus Glow!" Serena and the others watch as blue rings of energy begin to engulf her Saurus.

Aquos Saurus: 180 G to 230 G!

"What!?" Akira growled, not expecting her to have that card.

"Yup! Saurus Glow increases my Saurus' power by 50 Gs! Making him stronger than your Juggernoid!" Serena explained.

Juggernoid charged forward for a headbutt, but instead Saurus grabbed its head. The rhinoceros Bakugan lifted the tortoise into the air and brought its body down like a sledgehammer. Juggernoid returned to its ball form and rolled back down to Akira's feet.

Serena caught Saurus in her hands, then started gushing with happiness. "That's my Saurus! My super cool Saurus!"

Leonidas took in the entire scene with excitement. "So, this is a Bakugan battle…!"

Yuji grinned; sensing that his partner was in a better mood now. "Yup, and it's just getting started!"

Akira stomped his foot, infuriated at his loss. "Dang it! I won't let that happen again!"

Serena waved his threat off, confident that she'd keep beating him. "Try it. Your turn to go now," She said.

"Tsk. I know just what to use against you too," Akira reached into his case and pulled out a card. "Gate Card, set!" He tossed out another Gate Card next to his other one. "Bakugan brawl!" Akira tossed his Bakugan towards the card he had just placed. "Bakugan, stand!"

The Bakugan that rose from the sandy mist resembled a scorpion. It raised its spiked tail into the air threatening glaring at Serena.

Subterra Stinglash: 240 G!

Serena was shocked once more at the large battle power of Akira's Bakugan, but she refused to let it show. She knew full well that the boy wouldn't shut up if she acted intimated. "Maybe, I'll be able to boost my power higher than his again?"

The blue brawler brought Saurus back out. "Bakugan brawl!" She tossed him towards Akira's Stinglash. "Bakugan, stand!"

Saurus stood once more to face off against Akira's Stinglash.

Aquos Saurus: 180 G!

"Again? You're really over confident aren't you?" Akira smirked.

"Not over confidence when I know that I can beat you!" Serena exclaimed.

"Then beat this! Gate Card open!" Akira commanded.

Beneath both Bakugan the Gate Card illuminated with a brown color before revealing what it was. Stinglash roared as its power from standing on top of its character card.

Aquos Saurus: 180 G to 260 G!

Subterra Stinglash: 240 G! to 360 G!

Serena was taken aback by the usage of Stinglash's character card. She should've realized that he had something planned when he put down another Gate Card. "I have to do something…!" Serena glanced down at her two other Ability Cards. "This one! Ability Card activate! G-Power Swap!"

"Ha! I knew you might pull that! Ability activate! Terra Crunch!" Akira called out. The card in his hand glowing brighter as Serena's card began to dim in light.

"W-what did you do!?" Serena gasped.

"I knew you might use a G-Power Swap like the one your brother used against Shuji! Terra Crunch negates any ability used before it as long as I have a Subterra Bakugan on the field!" Akira explained, triumphantly.

Yuji grimaced at the implications of this move. "She walked right into Akira's trap."

Leonidas agreed. "From what I can tell had she truly been paying attention then she would've noticed he ploy. That buck toothed boy took advantage of her carelessness."

"We're gonna have to avoid making these mistakes once we battle, Leonidas," Yuji made a mental note.

"Agreed."

"Go! Stinglash!" Akira commanded.

The scorpion Bakugan hissed before swinging its tail into Saurus' neck, landing the killing blow against the Aquos Bakugan. Saurus turned back into ball form and rolled next to Serena's feet. "Saurus!"

Akira caught his Stinglash. "Ha ha! Not feeling so smart now, huh!?"

Serena picked up her Saurus, giving the Aquos Bakugan a salute. "You fought valiantly, young Saurus. Rest now and leave the rest to your comrades!"

Yuji just pinched the bridge of his nose.

"Are you going to start now or…?" Akira didn't know what he was watching.

Serena took a moment to gather her thoughts. "I only have one Ability Card left and three Gate Cards. I can't risk using this ability too soon, so I need to rely on my Gate Cards and hope he doesn't have a counter. I'm just getting started!"

"Gate Card, set!" Serena tossed down another Gate Card. "Bakugan brawl!" Serena sent her Bakugan flying towards her Gate Card. "Bakugan, stand!"

The Bakugan that rose this time was an Aquos Serpenoid.

Aquos Serpenoid: 150 G!

Akira laughed. "Are you stupid!? That thing is weak!"

Serena smirked. "Then why not put me in my place like you said you would?

"Fine then. Bakugan brawl!" Akira sent his Stinglash back out for battle. "Bakugan, stand!" The scorpion Bakugan hissed dangerously at the Serpenoid.

Subterra Stinglash: 240 G!

Akira lifted an ability card. "And I'll make sure that you can't even attempt a comeback! Ability activate! Desert Thunder!"

Subterra Stinglash: 240 G to 340 G!

"It increases my Bakugan's Gs by 100 Gs!" Akira explained.

Yuji worried for his sister, hoping that she had something planned. "Serena…"

The usually boisterous girl was silent for a moment, confusing everyone. "Gate Card open."

The Gate Card below the Bakugan began to illuminate brightly, revealing itself to be a Command Card. "Mine Ghost!" Serena exclaimed.

"What!?" Akira gasped.

"Mine Ghost?" Yuji questioned.

"When there are two or more Bakugan standing on this Gate Card, the battle automatically ends as a loss for both of us!" Serena explained.

As Serena explained the card's effect both Bakugan were enveloped in a bright flash of light, turning back into ball form and returning back to their users.

Leonidas hummed in approval. "She managed to turn the situation against her into an even playing field."

"Yeah, and Akira doesn't have any Ability Cards left. Which means that Serena holds the advantage now. Both of them are down to their last Bakugan," Yuji said.

Serena smiled confidently as the odds were now in her favor. "It all comes down to this, shorty."

Akira was fuming in rage, his strongest Bakugan had been beaten so quickly. And when he had finally managed to get one over her too! "Shut up! I'm going to win this one!"

"Bakugan brawl!" Akira tossed his Bakugan onto the last Gate Card.

The Bakugan that appeared was a Subterra Saurus.

Subterra Saurus: 180 G!

Serena sent her's out next. "Bakugan brawl! Bakugan stand!"

Serena's final Bakugan resembled a massive robot with two large holes on its chest.

Aquos Robotallion: 200 G!

"Gate Card open!" Akira commanded.

Subterra Saurus: 180 G to 230 G!

"That's not gonna work, shorty! Ability activate!" Serena smiled confidently, knowing her victory was guaranteed. "Abyss Ruler! I gain 100 Gs!"

Aquos Robotallion: 200 G to 300 G!

Robotallion's chest began to glow with energy as it charged up its attack. Two massive lasers were fired out of its chest and directly into Saurus. The rhinoceros Bakugan cried out as it reverted back to ball form.

Time resumed after the battle ended. The birds in the sky flapped their wings once more as if they hadn't been frozen for a certain amount of time. Within the park stood a victorious Serena over a defeated Akira, who was wallowing in defeat.

Serena huffed, proud of her victory. "I guess we now know who the stronger of the two of us are!"

"Shut up!" Akira climbed back to his feet. "I-I'm not gonna take this! I'll fight you in the tournament and beat you for everyone to see!"

Serena felt a sense of deja vu. "Well…in that case. Let's be rivals!" She requested.

"Eh?"

"That way it'll be more climactic when I beat you again!"

"As if! I'm gonna beat you next time…you…you…idiot!" He screamed before running away from her.

"Idiot!? You stupid shorty! Get back here!" Serena was about to give chase until Yuji grabbed the collar of her dress.

"Okay, Serena. You had your fun," Yuji said.

"Eh? Yuji? When did you get here?" Serena asked.

"...I've been here the whole time."

"I never noticed you."

"I feel like I should be insulted," Yuji sighed. He then patted her head affectionately. "Good job, winning your first brawl, Serena."

The girl blushed under her brother's praise, enjoying the feeling of him giving her head pats. "Yup! Just like my big brother!"

"Good job, Serena."

"Thanks-" She stopped instantly when she realized that the voice didn't belong to her brother. Light blue orbs slowly shifted to the Bakugan on his shoulder.

"You showed strength and adaptability in battle," Leonidas finally spoke to her.

Serena didn't respond; still shocked by the fact that Leonidas finally spoke to her. Yuji looked concerned for a moment before Serena yanked Leonidas off of Yuji's shoulder.

"YOU TALKED TO ME! You're finally opening up unlike Yuji!" Serena gushed happily.

"Hey!" Yuji cried.

"L-Let me go…!" Leonidas requested.

"You're just so cute, Leo!"

"L-Leo!?" Both partners questioned.

"How about we become partners instead, Leo?" Serena grinned.

"HEY!" Both partners yelled at her, while Serena just laughed at them both.

As Yuji tried to get him back from Serena's grasp, Leonidas could only groan in exasperation. "These siblings might be the death of me."

Chapter End

NOTE: Hope you guys liked the battle. Serena got to show her stuff and even got pushed a bit in this battle. Both her and Akira got arrogant in this fight, but Akira acted more carelessly by wasting his Ability Cards.

Leonidas finally talked to Serena after watching her win her first brawl and got to see exactly how brawling works. Which was one of the main points of this chapter. Think of Leonidas as a newborn who still needs to learn things.

Next chapter will finally be the start of the tournament, where you guys will get to Yuji and Leo working together against Shuji. Because he's the first opponent you fight in the tournament.

Have a great day!