A/N: Specter's weapon will be in scythe mode, I know this needs a specific eyecon but please bear with me.

Sirens filled the air of the city as the ambulance started to drive away, leaving a massive damage to the city as the previous fight had stopped, leaving three people injured.

Morning came as Y/N, Jack, and Aruto were still in the hospital, knowing what happened to the riders were brutal for them as the fight between Thouser and Zolda went wild. Y/N was laying down on his bed, Jack was holding a hand gripper squeezing it, as Izu was nursing the injured president on the other room.

Jack: Guess we knew that the third rider is evil.

Y/N: Tell me about it.

He said as the room was very quiet, not knowing what is the other rider's motives as shortly after, a knock was heard at the door, gaining their attention as the door opened, revealing that it was Sougo.

Sougo: Y/N! What happened to you guys?

Y/N: Oh, well, a third rider appeared, kicked the living hell out of us, and then this happened...

He explained as Sougo looked worried for both teens as two other figures walked in.

A man wearing some kind of a strange coat colored in gray, sporting also a gray scarf around his neck as he carries a book on his hand, approached Sougo.

???: Looks like you manage to take quite a beating.

The first one said as the other looked at Jack, having a scowl on his face as he looks at them.

The other was a teen, wearing a black tracksuit with red outlines, and sneakers as he crosses his arms.

???: Zi-O, are you sure that you gave these two the power that we possess? All I see is two beaten up teens.

He said as Jack was about to retort, but Sougo manages to handle it without any bickering needed.

Sougo: Geiz, Woz, I am certain that they are the ones who are right for our power. I know you didn't agree at first Geiz, but they will handle this responsibility.

Woz: As you wish my lord.

Geiz: I won't live up to that promise of yours Zi-O.

He said as Y/N sat up properly, looking at the three men in their room as he started to know them, telling what happened yesterday as they listened.

A week later...

Both teens were back at Hiden Intelligence as they resumed their internship, apparently, this is their last week with Aruto as more and more troubling news ensued, mainly, the Hero Killer Stain.

Aruto had took off with Izu as the two teens were stuck in the office, having Fuwa watch them, but his thoughts were far from noticing them as he was reading about what happened last week, the fact that Stain and Thouser's events happened the same day.

The two teens were sitting down on the couch, resting for the moment as they sigh for the moment, still thinking about the third rider.

Those thoughts were broken as an explosion from the outside was heard, along with Fuwa's phone, buzzing like crazy as he looks at it.

Fuwa: Damn it! Nomu's are moving through a neighboring city. But, what is that?

He asked as the two teens caught sight of Senkai and Gai from the security cameras as a horde of armed soldiers of A.I.M.S were behind.

Jack: This can't be good.

Fuwa: It never was.

Y/N: We'll take care of things here. You need to get to the next city to fend off some Nomu's.

He suggested as Fuwa glared at the teens, knowing that this would never be an option to leave them.

Jack: The pres would be here if anything goes wrong. We're sure of it.

Fuwa sighed as he looked at the two of them, knowing that they will hold on to what they said as he nodded.

Fuwa: Fine, just be careful both of you. Aruto would flipped out if something bad happens to you both. Plus, your school as well.

The both of them nodded as they head out of the office. As the two teens walked out of the building, Gai and Senkai were waiting for them, knowing that this would be an all out fight.

Gai: Hmm? No Zero-One? Guess he must gave up after last week.

Y/N: We're here to stop you Thouser. You and your lackey!

Senkai: I do have a name you know.

He said as right on cue Aruto came as soon as he heard what is happening through Fuwa as he stood behind them.

Aruto: Leave them alone Gai!

Gai: Ah, Zero-One, here to witness your companies demise?

He said as he held the Thousandriver on his hand, placing them on his waist as it straps over.

Aruto: Are you the one who unleashed all the Nomu's on the other city?

He asked as Gai just smirked proving that Aruto was right. Senkai on the other hand was just looking at his mentor.

Gai: With the help of those mindless monsters, I will gain all the people's attention, including the destruction of your humagears.

He said as soon after, Senkai started to walk over to the other teens, earning a curious look on the both of them.

Senkai: I knew it, I knew it all along.

He said as his back was turned from Gai, taking out a recorder from his pocket as he pressed the pause button on it.

Gai: What is the meaning of this!

Senkai: Don't you see? I just used you, Amatsu Gai.

This caught him off guard as well as the two teens, but Aruto begged the differ.

Aruto: Senkai reached out to me through private lines, taking in some informations and telling them of your plans. I never knew that you would stoop so low just to destroy my company.

Senkai: In case you are wondering, let me introduce myself one more time.

He said as he stood beside the two teens looking at them as he looked at Gai one last time.

Senkai: I'm Senkai Goku, wielder of the third generation Kamen Rider. Fighting for what is right.

He said as this infuriates Gai as he ordered the soldiers to dispose them, transforming into armored soldiers with a seemingly same drivers as the Kamen Riders as the three teens stood their ground.

Senkai: Hope you two are healed up, this is going to be one hell of a fight.

He said as the three of them smirked, extending their hands to the side as they look at their enemies.

Y/N/Jack/Senkai: Kiva!/Specter!/Chalice!

Three drivers appeared out of their waist as Jack have the same driver as Ghost, Senkai holding out a card, while a bat started to fly over Y/N.

Kivat: Ikuzo! Ga baito!

The bat bit his hand as veins started to appear as the three riders are ready.

Y/N/Jack/Senkai: Henshin!

Chalice Rouser/Ghost Driver: Change!/Kaigan! Specter! Ready Go! Kakugo! Do Ki Do Ki! Ghost!

As the three of them change each number were inscribed on their belts, having "0" and "9" on Kivat's wings, "17" on the center for Specter, and "5" on the side for Chalice. Gai had ordered the soldiers to attack the teens as he was going for Aruto as the fight began.

The soldiers obeyed as the riders started to get to their fighting stance.

Chalice grabbed his Chalice Arrow and Specter grabbed his Gan Gun Hand already in scythe mode as the three attacked, fending the soldiers one by one as they split up.

From a top of a building, a man was gazing down on the riders, having an open book on his hand as he smiled.

Woz: Iwae! For a new Kamen Rider has joined the ranks of Y/N and Jack. Senkai Goku, wielder of the powers of the third generation riders. Your fights are already begun, don't let us down the three of you.

He said as he closed the book and soon enough he was gone.

Specter swings his scythe around, guarding and attacking the soldiers as they shoot him, managing to dodge them nicely.

Specter: Is that the best you can do?

He said as he pulls the lever and pushes it, channeling the power as a blue eye started to appear behind him.

The scythe glowed in a blue color as he swings it, hitting all of the soldiers in his sights, signaling that his fight is now over.

Ghost Driver: Omega Fang!

Chalice on the other hand wasn't going easy on them, rather, he was already finished once he stepped foot in front of them. Putting the Chalice Rouser on an empty slot of his weapon as he draw two cards, sliding them on the rouser.

Chalice Rouser: Bio!

Chalice Rouser: Chop!

Vines started to shoot out of the weapon, binding anyone who is near him as he pulls them close, sending out a powerful punch as they flew out for a good meter, not wanting to get back up as Chalice turned around.

Chalice: Not worth my time.

Lastly, on Kiva's side, Kiva was punching and kicking the living daylights of the soldiers, having a hard time keeping him in track as he pulled out something from his belt.

A red fuelette was placed on the mouth of Kivat, sliding it down as Kivat chimed a bit.

Kivat: Wake up!

He flew off from the driver as Y/N raised his right leg, Kivat who was flying around it broke the chains open, revealing a wing on his leg. Using his free foot, he jumped up in the sky, making a backflip as he extends his right leg out as he delivers a vicious rider kick, hitting its mark as it left Kiva's logo on the shattered ground.

Y/N: That takes care of that.

He said as he looks at Zero-One, as he was already done with Thouser.

01 Driver: Rising Impact!

With Zero-One delivering the final blow to Thouser, the fight was over, making Thouser retreat as he promised to be back for a vengeance.

Having to transformed back to their normal form, Y/N couldn't help to notice that the internships were over, more importantly, another rider joined them in their fight. He was surprised that he had double cross his mentor, but for now, that can wait, as the three of them are now banded to fight as Kamen Riders.

To be continued...