AN: So… I'll admit, I don't exactly know the most about Kamen rider… But that's fine, right? After all, this is fanfiction, and I have Tvtropes and wiki's to help me! So then! Let's do this! Or, at least give it my best shot! THETWOMIND! FANFICTION! BEST MATCH! By the way, lots of canon for Kamen Rider will be ignored her, this is my version of it, so if I want to completely ruin Build and make my own version, I can. So I will. I'll probably make a proper version one day but… Until then, you'll need to put up with my stupidity!

Harry Potter looked out of the window as the car stopped, getting out, followed by a girl that was much cheerier than she should have been for where they were. "You sure you want us to go here?" He asked the girl, getting a roll of the eyes for his troubles.

"Of course I do! Besides, think of all the goodies I can get from this place… Oooh I'm so excited!" She exclaimed, bouncing on her feet excitedly.

"I can tell." He grinned at her, spinning what seemed to be a tiny bottle of some kind in his fingers.

"Hey! Give that back!" She exclaimed, trying to take it from him.

"It's one of mine." He warned her, putting it into an odd holder attached to a belt he was wearing, which vanished from sight.

"No, it was one of mine! I recognised the colour!" The girl argued.

"No, mine. I specifically made sure I only brought mine in my bag. I packed yours into your bag." He explained, messing with her hair.

"You promise you only have your bottles?" She asked, looking at him suspiciously.

"Yes, I promise." He promised.

"Alright then! Come on! I wanna go see!" She said, switching from suspicion to excitement instantly.

"Alright, I think it's here." He said, heading into a building, the leaky cauldron…

"Ugh, smells like an abandoned bandit shack." The girl complained, covering her nose.

"You've never been in one." Harry pointed out.

"So? It stinks!" The girl whined, disgusted by the stench.

"I guess, let's just get the supplies and get out of here." He decided, heading through the backdoor with the girl, looking at the brick wall in front of them, trying to figure out how to get past it.

The girl's eyes shone, equations flying through her mind… And then, she reached forwards… And tapped a couple bricks, causing the wall to split in half. "Oh... I thought it would explode…" The girl mumbled embarrassed.

"Hey, at least it's open." He pointed out, heading into Diagon Alley…

"True!" The girl agreed, skipping after him with a happy hum.

"So, first is… Gringotts." Harry said, checking a list that he had in his hands.

"That's the building there right? Want me to just go get the money?" The girl offered.

"No, we can both go." Harry decided, ignoring the looks the two were getting for their odd clothing styles… The girl was wearing a pale fleshy coloured jacket, with a large bulky belt buckle that had a hand crank on its side, her eyes were silver, and her hair was black. Harry was wearing a golden jacket, with the same belt and buckle, as well as the crank on the side. Attached to the belt itself was a phone holder, which he kept his phone inside of, it was locked of course, locked to the belt, as well as the opening itself being locked.

"You think we should have brought her with us?" The girl asked as the two made their way to the building.

"We were going to, she just wanted some time away from you and your explosions." Harry reminded her, as he entered Gringotts.

"Oh yeah!" The girl grinned embarrassed, having forgotten that.

"You're an idiot sometimes Banī, you know that?" Harry told her, messing with her hair playfully.

The girl, whose name was Banī, gave a playful grin at him, shoving him a little, which was all she could do with her pretty small stature. "Only sometimes! The rest of the time, I'm a genius scientist!" Banī declared, amusing Harry.

"Yeah, you are. Anyway, money." He remembered, approaching what looked like a Goblin. "Excuse me, is this where we get money?" He asked, hoping he was right.

The goblin looked at him in disinterest. "Yes. This is. Do you have a vault to get your money from?" The goblin, since it was difficult to tell if it was male or female, asked, uninterested.

"Well, I have a key, but I've never actually been to the vault before." Harry explained, showing the goblin his key.

The goblin took the key, examining it for a moment. "This seems to be authentic… Very well. I shall call for someone to take you to your vault." The goblin told him, pressing a button on the desk and speaking into a small device. "Griphook shall take you to your vault now." The goblin said as another one walked over, leading Harry into the building.

Banī moved to follow, but was blocked by the goblin. "Only family and guardians may go with key holders." The goblin told her.

"But I'm his sister in everything but blood!" Banī whined, before she was allowed to follow, racing after the boy she viewed as her big brother.

Vault 687

The two humans and one goblin arrived at Vault 687 on a mine cart, Banī and Harry having enjoyed the ride.

"Can we go faster on the way back up?" Banī asked hopefully.

"One speed only." Griphook stated, amused by the girl, if only slightly.

Harry watched as the door to the vault was opened, collecting coins and putting them in a pouch, which he put on his belt, using the same locks as those that protected his phone.

While Harry was doing that, Banī was investigating the vault door next to Harry's, specifically the symbol on the front, it looked like a gear, with a jagged line splitting it into two segments… Below it were two small slots, shaped like tiny bottles… With small rail-like objects on the bottom of the slots. Banī took two of the small bottles she and Harry carried with them, a blue one and a red one, and shook them, twisting the caps at the top and slotting them into the door…

"RABBIT! TANK! BEST MATCH!" The door announced, getting the attention of Griphook, who hurried over to investigate what Banī had done.

"You opened it! How did you open it?" The goblin asked in shock, the door opening in front of them to reveal an almost empty vault, except for a small box that sat on a table. Griphook sniffed, trying to regain composure. "Well, as you opened the vault, which even we have never been able to manage, you have full access to whatever is inside." The being told the girl, intriguing her.

"Cool!" She exclaimed, before she turned to Griphook confused. "Um… This might be sort of rude… But what gender are you?" She asked.

"I am male, but I understand that humans and wizards have difficulty recognising gender differences for goblins, as we all look very similar." Griphook explained.

"Thank you!" She thanked, bowing politely before she ran into the vault, opening the box excitedly. Inside of the box were two more of the small bottles, one of them was an emerald green, while the other was crimson red, on the caps were two letters, a B and a G. "Ooh… What do these do?" She muttered to herself curiously, putting them away somewhere and exiting the vault, removing the two bottles from the door which caused it to close.

"So those bottles open the door…" Griphook noted.

"I guess! Harry, you ready to go?" Banī shouted to Harry who quickly left his vault, letting Griphook close it before they returned to the surface.

As they made their ascent, Harry's minded drifted back to the past…

Two years ago…

Harry Potter, a nine year old boy, was hiding in the park from Dudley and his gang, there was a new girl at school that Dudley had decided to show who was in charge, before the girl beat the round bully up, of course, Dudley told his parents, who blamed Harry.

"What are you doing in a bush?" A voice asked Harry, as he looked around, finding a girl sitting on a branch of a nearby tree. "Come on up here! It's much more comfortable!" She called, extending a hand down, which he took, being lifted into the tree by the girl, who only used one hand to lift him.

"Thanks…" Harry mumbled quietly, noticing Dudley nearby.

"What's wrong?" The girl asked him worried.

"It's Dudley, my cousin…" He whispered, as Dudley stomped around the park, searching for his victi- I mean, cousin…

"Oh, him…" The girl's face went from cheerful to annoyance for a moment. "You're not like him, right?" She asked, getting a rapid head shake from Harry, who wanted to be nothing like his rotund cousin. "Alright then! Hey, wanna see me do something cool?" She asked with a grin.

"Sure." Harry agreed, wondering what she would do…

The girl reached into her bag, pulling out a belt buckle, which she placed near her waist, a belt appearing and wrapping around her. Then, she pulled out two small bottles and shook them, jumping from the tree in front of Dudley, she put the bottles into slots on the belt.

"Rabbit! Tank! BEST MATCH!" Her belt seemed to shout, as she turned the crank on the side… In a flash of light, she changed, she was now wearing a black, formfitting tank top of some kind, with red and blue segments all over, including two long gloves, the left was blue, while the right was red, on her legs, she wore long boots that went up to her thighs, the colours flipped on them, she had a black skirt on that seemed to have red and blue stripes repeating on the inside of it, but it was hard to tell… Her hair had changed colour, going from a simple black, to red and blue, with two strange objects in her hair just above her eyes. "Hagane no moonsault! RabbitTank! Yeahhh!" The belt shouted again, as the light faded. The girl grinned, walking close to Dudley, and whispering in his ear, causing him to cry and waddle as fast he could away from the girl.

"That was awesome…" Harry whispered, awed by the girl's transformation.

"It was nothing much…" The girl mumbled, blushing a little as she looked at the ground. "Just something I whipped up." She explained.

"It was amazing!" Harry exclaimed, almost falling out of the tree as he flailed his arms to show just how amazing he thought it was.

The girl blushed, before she jumped up into the tree, changing back to her previous form without warning as she landed. "My name's Banī, Banī Bakudan!" The girl introduced herself, sticking her hand out.

Harry took it hesitantly. "Harry Potter." He introduced back, as his destiny changed course in that instant…


Harry watched Banī enter Ollivanders, following her calmly.

"Ah… Mister Potter… It seems like only yesterday that your parents bought their first wands…" Ollivander said, as he appeared from a dark corner of the room.

Banī made a face, getting the attention of the old man.

"Ah, and Miss Bakudan, I am unsure if I will be able to find a suitable wand for you." The wizard noted. "But, I shall give it my best attempt." He decided, reaching for a box, opening it and taking a wand out, which he handed to Banī. "Go on, give it a wave." He said, searching through boxes.

Banī waved the wand, causing it to knock down a box.

"No! No! Definitely not!" Ollivander decided, taking the wand back.

More wands were tried, and failed.

Ollivander looked ready to give up, before his eyes landed on Banī's belt… "I wonder…" He muttered, turning around and pulling out a wand from a dusty box. "Perhaps… Yes…" He turned to Banī, putting the wand in her hands carefully. "Walnut, eleven inches… Core, a strange material I found in my garden… Oddly reactive, easily moulded into a wand core." He stated.

Banī gave the wand a flick… As her belt started to flash… "Rabbit! Wand! Spell match!" It called out, the room flooded with wind.

"A perfect match…" Ollivander noted, smiling serenely… And then, he turned to Harry…