3rd POV(Tokyo)

In Tokyo,there nobody around at Tokyo and it silent but suddenly we see a building crash down and two figure landed on the ground as it show one Kamen Rider fighting another Kamen Rider as it reveal is Build and other Build but it Dark Black and Red.

Kamen Rider Dark Build:Give up Build.You won't even try bother defeat me.

Kamen Rider Build:*Hold his Pain*No!I must save the humanity and my friends from you!

Build summon his Drill Crusher and charge at Dark Build.

Build slash Dark Build a bit damage as Build insert his Rabbit Fullbottle to his Drill Crusher and he press the trigger.

Drill Crusher Announcer:Ready!Go!Vortex Break!

The Drill Crusher start spins such that it creates an energy whirlpool as Build charge at Dark Build and slash him with his Drill Crusher but then his Drill Crusher can't go through and exploded as Build got back away a bit.

Kamen Rider Build:*Eye Widen*What?!

Kamen Rider Dark Build:*Smirk*Even your weapon won't kill me as well.

Kamen Rider Build:*Angry*That it!

He rotate the lever on his Build Driver and ready to deliver his kick finish to Dark Build.

Build Driver Announcer:Ready!Go!Vortex Finish!

But then Dark Build did the same as Build to deliver his kick finish.

Dark Build Driver Announcer:Ready!Go!Dark Vortex Finish!

Build jump high and deliver a red and blue kick and Dark Build jump high and deliver a dark black and red kick as they kick each other and Build screamed.

Kamen Rider Build:AAAAAAAARRRGGGGHHHH!!!

Suddenly his Kamen Rider Build Suit start to torn apart until when he is human form,Dark Build then kick through him as he got exploded and fall to a ground as he try get back up but then Dark Build start walking toward him.

Kamen Rider Dark Build:I told you give up now but you won't listen.Now I have to kill you now.

Grant Kickson(Previous Kamen Rider Build)

Grant:*Hold his Stomach*I...haven't finished...

Dark Build then grab his neck up.

Kamen Rider Dark Build:Don't worry.I'll let you rest for now.

He said while his right hand suddenly turn into a blade and stab Grant stomach.

Grant:*Scream*Aaaahhhhh!

He cough as a lot of blood coming from his mouth and Dark Build throw him to the ground.

Kamen Rider Dark Build:Kamen Rider Build is gone now!No one can save the city now!Hahaha!

He then open up a red portal and got in and the portal close.Leaving Grant holding his wound from his stomach as the weather start to rain.

Play This:Change My Future by Koda Kumi

https://youtu.be/7vozR1rzpGM

Grant:I....I'm sorry everyone.....I couldn't.....save you all....Papa...Mama...Mamiya...

He close his both eyes and let go of his hand but then a person start running toward to Grant.

Mamiya(Grant AI Servant)

Mamiya:Master!

She scanned Grant body but then it says that he is deceased.Her tears start drop to Grant hand.

Mamiya:*Tear up*Master...

3 Hours Later...

After Mamiya buried Grant body and put a lot of flowers at Cemetery,she went back to her master house.When she start packing his master stuffs and found a notes for her,she open it and read it.

Dear Mamiya,

  When I'm first create you,I was happy that my AI experiment have finally work.You and me have a lot of fun times together and battle a lot of smashes.But then,I feel like I'm gonna died in someday...If I died or deceased,I want you to help me a favour.That is help me get my Build Driver out and give someone that can help the humanity.I counting on you Mamiya.Goodluck.

After she read finish the note and look at the Build Driver,she pick up the Build Driver.

Mamiya:I promise you Master.I will find someone that can defeat those Smashs.

Meanwhile

We see a glowing gold spirit coming through the window and then look at a boy sleeping on his bed.

Gold Spirit:I'm counting on you.When you grow up,you will be another me to protect the world.

The gold spirit then go inside the boy body.

Get Ready For The Next Kamen Rider Build!

Notes:

-Mamiya is from a Korean Webtoon Comic called Housekeeper.