(Disclaimer - I do not own any of the featured characters/settings/etc from either of these brands. RWBY is a property owned by RoosterTeeth, Warner Media and Monty Oum, BIONICLE is owned by Greg Farshtey and The LEGO Company. All rights go to the creators of the franchises and it's characters)

BIONICLE/RWBY: Best of worlds

Prologue:

Gathered friends, listen again to our legend of the BIONICLE. In the time before time...our island home Mata Nui named after the great spirit himself was under siege from his dark brother Makuta who cast Mata Nui into a deep sleep, intent on releasing his shadows upon us all. But hope was found in the form of six noble Toa, masters of their elements united to challenge the dark forces Makuta unleashed upon the island. It was their duty to inspire and protect the Matoran, it looked as if the battle would be eternal. Until a seventh Toa named Takanuva, the master of light rose to challenge the mighty Makuta and banish his shadow once and for all. Even though the Toa had achieved their destiny and awoke the great spirit of Mata Nui, the years of war had stripped the island of its former glory, and now it is time for us to depart our once island paradise and find a new land to rebuild our civilisation's way of life; stronger and greater than before. But wherever the light shines brightest…the darkest night will be cast in its wake. As the unrelenting shadow of Makuta would follow us to the new world we would call home, intent on bringing his dark wrath down upon us all who would dare appose his might and claim this new realm as his own.

Kini-Nui, The Great temple, dusk.

Tahu, the Toa of fire had just finished loading the last of the light stones onto the chariot they had been helping the Matoran construct these past few weeks following the defeat of Makuta Teridax and his Rahkshi, thanks to the help of Takua the chronicler of the Matoran, who had been chosen by the Kanohi Avohkii, mask of light which he had found. This mask transformed him into the seventh Toa Takanuva, the master of light and vanquisher of Makuta's shadow. Despite their victory, the fire village of Ta-Koro, the ice region of Ko-Koro and the underground earth village of Onu-Koro had not survived the conflict, leaving them uninhabitable as a result. Since then the inhabitants of the island of Mata Nui had been preparing to leave the island for new lands where they could settle down and start a new life. Various equipment had been packed and loaded onto a huge chariot for the journey ahead, including weapons, tools, books, and even some of the staffs and balls used for kholi games.

While they did not know where their travels would take them, they did know it would lead them far from their old home.

Before departing, the elder of Ta-Koro's fire tribe. Turaga Vakama had gathered everyone for a final speech before leaving the island for good.

"Matoran and Toa of Mata Nui, the great spirit has guided us through dark times and showed that we can still triumph when all hope is lost." Spoke the Turaga of fire.

"I can't believe he's actually doing before we leave." Grunted Tahu, Toa Nuva of fire.

"Just relax Tahu, it'll be over in no time." Replied Kopaka, Toa Nuva of ice with a composed tone.

"Heh, sure it- "Tahu spoke sarcastically before the Toa of ice cut him sort.

"Yeah, it will actually." The master of ice replied abruptly as Vakama continued his monologue.

"Makuta and his shadow has been vanquished forever, but at the cost of our home. Not all is lost though, the Toa have found a series of underground tunnels beneath Makuta's lair. They will lead us to a new land and hopefully a brighter future. Let our journey...begin!" Said the fire Turaga.

With that, everyone in the crowd chanted the three virtues "unity, duty, destiny". They gathered the last of their supplies and bag-packs. Then they headed down the cavern towards the tunnel.

"Whelp, let the journey commence." Said Onua, Toa Nuva of Earth

The Matoran villagers worked together to pull the chariot, the Toa and Turaga taking turns to assist them as they moved deeper underground.

"Any idea where these tunnels will take us?" Hali asked Takanuva, the Toa Nuva of light.

"No idea Hali, only time will tell" Takanuva replied to the female Ga-Matoran

"I hope it's somewhere pretty with areas of land we can use for kholii games." Said Hewkii

"Let's not too carried away Hewkii." Commented Onewa, the Turaga of Stone

"Of course, Turaga." Replied the young Po-Matoran.

A few minutes later, they finally reached the entrance to the network of tunnels.

"Takanuva, as the Toa of light you shall light our path through the journey that is now ahead of us." Looking as Takanuva as he spoke.

"As you wish Turaga Vakama." Replied the Toa of light.

With that, Takanuva used his Kanohi Avohkii to make his physical form glow like a firefly. Everyone else followed behind him as they entered the tunnels.

"Let's go." Shouted Jaller the Ta-Matoran

1 day later.

"Are we out of here yet?" asked the Le-Matoran Kongu

"No." Kopaka replied, still calm and composed as always. He had no idea where these tunnels were taking them, but he had faith that it would bring them somewhere.

2 days later.

"Sometimes I think we are going in circles." Hewkii complained

"Tell me about it." Said Pohatu, Toa Nuva of Stone.

3 days later

"We must be nearing an exit sooner or later!" The Toa of fire said to himself, frustration in his voice from endless walking.

Onua turned to Kopaka, who was scanning the area around them with his Akaku, mask of x-ray vision Then Onua tapped the master of ice's shoulder.

"Ice brother, you alright?" The Toa of Earth asked nervously.

"Yeah, just thought there was something watching us." Replied the Toa of ice, yet there was a sense of unease in his response.

On that note, the convoy continued forward on their path. What they did not know what that Kopaka may have had reason for being on edge. Someone, or something else was down here with them. Just out of sight, within the darkness was a being unlike anything they'd encounter before. She had only discovered the maze of tunnels 3 days after the Toa, her skin was deathly white, but brittle like a skeleton and covered in black veins. She sported a jet-black robe, which was brightened by red patterns that matched her irises. A black diamond shaped mark at the centre of her forehead, her pale hair tied into a bun sporting six offshoots with ornaments suspended from them. She was not of the Matoran universe, while she did not know what this place was, but she did know that something has called her here. A voice had been echoing in her mind and her search for the origin point brought her down here via a portal which somehow opened within her own realm. She'd been searching the tunnels for days but still no closer to finding the source of the mysterious voice. Then suddenly, she stopped. Turning her head to the left and on the ground was some kind of object. As she walked through the mist, she kneeled down to study this object. The object was the Kanohi Kraahkhan once worn by the leader of the brotherhood of Makuta, Teridax. Now the great mask of shadows was littered with dust and cracks all over following the battle with Takanuva. The dark female figure gently picked the mask up and dusted it off, careful not to cause any further damage. As she looked into the two eyes holes of the kanohi, the female could feel a powerful and deathlike aura emanating from this damaged mask.

"So, Who, or what are you?" She asked inspecting the mask and its primitive design.

"Destiny." The voice she'd been hearing was coming from the Kanohi Kraahkhan. A voice the Toa hoped they'd never hear again, the voice of Makuta Teridax.

A few seconds passed, but then the shadowy female raised her hand and opened a crimson portal which she walked into and vanished, back into her realm.

4 days later….

"I, think I can see a light." Toa of fire shouted to his comrades.

"I see it too." Replied the Toa of light.

Tahu pulled out one of his magma swords and ignited it before joining Takanuva upfront. As the two them got closer to the source of the light, they noted it was a glowing symbol. In a shape that they had seen so many times before.

"The symbol of the three virtues." Spoke the Toa of fire In Awe.

"You mean unity, duty and destiny? Laugh-joking you must be fire spit- "Before the Toa Nuva of air could finish, he stopped mid-sentence, his eyed widened when he realised Tahu was right. The object in front of them had two small points were Unity was on the left, Duty to its right and Destiny in the middle as always.

"Incredible." Spoke Turaga Vakama.

Tahu reached his hand out to touch the symbol with his hand, his fingers sank into its liquid form and he slowly pulled them back out.

"it's not solid, must be some kind of inter-dimensional portal." Tahu said in disbelief.

"Makes you wonder what could be on the other side?" Said Toa Nuva Onua as he scratched his head, uncertain yet calm.

"Well, there's only one way we can find out Earth Brother." Kopaka replied.

And so, the Toa, Turaga and the Matoran pulling the chariot began to head into the portal in front of them. Uncertain of what awaited them on the other side.