I do not the Toaru series,Strike the Blood or Kamen is my first time writing a fanfiction and this will be the under a series named Sigma Saga,which is the crossover of Kamen Rider and animes,except its flagship will be the Sigma Object, the different version of various rider collectibles. This fanfiction's Sigma Object will be the Sigmabottles.
A Certain New World of Build
Prologue
On the devastated battlefield,five kamen riders also known as Team Build has been defeated. The one victorious in front of them an unidentified Kamen Rider. The only thing could be seen about the Rider is only a Build Driver with a Fullbottle adapter that shaped like Cerberus.
"Damnit,he easily beat us up even though we used our most powerful form", said Ryuga,one of the defeated riders.
"He uses three Fullbottles and an unknown Trigger to transform,how could he get three Fullbottles that represents Touto,Hokuto and Seito?", said Kazumi,who confused by the unknown Rider's transformation trinkets.
The unidentified Kamen Rider,only known as Tripolus walks toward them,showing the Pandora Box and said "Looks like you guys are really useless. There no need for this world exists from now on,". He then show two suspicious-looking Fullbottle.
One on Tripolus's left hand had complete technological advanced armor plate and coloured Shielding Cap is rainbow- coloured and the bottle display eight weird-looking dragon.
The other one have some sort of advanced medieval-style sliver armor plating and coloured blood red. The Shielding Cap is silver-coloured and the bottle display an advanced silver-coloured spear and a hand with patterned line on it.
"I've never seen those Fullbottles before", said Gentoku,who is completely shocked by the bizarre-looking Fullbottles.
"Of course you never seen these fullbottles.I created it using essence came from another world", said Tripolus proudly.
Essence from another world? said Sento,who is confused.
"Shall we begin the ceremony?", Tripolus saying the phrase that almost to Sento's as he shake the bizarre-looking Fullbottles and then open the Shielding Cap. Tripolus then began putting the bizarre Fullbottle into the Pandora Box and the Box begin to spin violently as it become the orb of light.
The orb begin to sprout "light tentacle" and approach Tripolus. He's terrified and said "Wait...wait,wait,wait,wait,wait,NOO!" but it just too late for them as they being stabbed and absorbed into the orb.
"Well that was unexpected", said Ryuga deadpanned.
The orb goes up in the air and began caused Ryuga and Kazumi hang their head and feel curious about what will happen.
"ITAAA!"
Sento smack their head and said "What are you two idiots doing!? We need to get out of here and warn the people about it"
The riders leave the battlefield and set for Touto.
(At Touto)
The people of Touto focusing their eyes on the news.
"An unidentified orb of light appear in the sky and it's government don't know what just happen but they will find out what is happening"
"Sawa,Misora...", said Sento calling two girls that watching the news.
"Sento,what just happened? What did that Rider do?", said Misora,who worried about what happened.
"I'm not sure,but what just happen caused him being absorbed into that orb of light", Sento confirmed.
The orb now become pitch black with incantation pattern to form. This cause the citizens of Touto panicked.
"WE NEED TO STOP THAT ORB-", said Gentoku loudly before being interrupted by Sento.
"THERE'S NO WAY TO STOP IT", said Sento loudly while arguing with Gentoku.
"So there's no way to stop it?", said Gentoku questioning Sento.
"I'm not sure,but lets just pray that the world isn't going to end", Sento answered with depressed feeling.
Soon after that,the orb exploded and destroyed the world.
A/N:That is the end of the Prologue and the beginning of the story. This story will be the triple crossover of Kamen Rider Build,Toaru series and Strike the Blood. It will have its own story and consists of Story Arc.Anyway,I will be creating forums during or before making the next chapter. One forum for questioning me,one for giving comments and one will act as a place for sending fan arts(crossover arts like Misaka,Kuroko and Ryuga;Touma,Index and Sento etc.,rider's form idea like Cross-Z Electro,Cross-Z Railgun,Build Majin Trinity and more forms that I will introduced in the later chapter and fanmade comics of the Sigma Saga series)because I can't draw ,for reminder to those reading this and Toa Solaric's Armored Rider's Date A Live Chronicle,please try to make fan arts of Gaim,Baron,Ryugen and Zangetsu's Spirit Armor Form for Solaric himself.