Rikku and Goku stared at each other, never breaking eye contact even as Rikku hovered back to create distance. As she did so, Goku noticed that she was trembling. Good, her rage would make her sloppy. As Goku was making this assessment, Whis noticed something off. He told Beerus,
"Look closely, my lord. The index finger of our new visitor's right hand."
Beerus looked up and narrowed his eyes upon seeing the time ring. He asked,
"Whis, is that-?"
"It is."
Goku surveyed the area around him and took note of Vegeta, but was confused when he saw Beerus. He asked Zamasu in his mind,
"Who the heck is that?"
Zamasu replied,
"That is the god of destruction of this universe, Beerus. He's above the kais but below the omni king. And far stronger than you."
"Really? I'll have to challenge him at some point."
Goku then brought his attention back to Rikku, rushing at her and throwing wild jabs which she barely managed to block. She was quickly forced to power up to super saiyan 2, the aura from the transformation pushing Goku back. Rikku then began launching punches of her own, Goku swiftly blocking and deflecting them. Now Goku was forced to put in work to deflect the attacks, but he could still sense that he held a slight advantage in power.
He then unleashed his full power in one shot, punching Rikku in the gut. Afterwards he reeled back and kicked Rikku away, but she quickly rebounded as Goku began firing ki blasts at her. RIkku began flying around to dodge them all. However, she was eventually forced to fire a kamehameha, destroying the ki balls.
As she rushed in for another attack, she was suddenly punched in the face by Vegeta, who screamed at her,
"What are you doing, you fool?! He killed Goten, why are you still holding back?!"
"I was just getting a gauge of his power!"
"Goten's my son too, and I will not stand by while you let his future self's killer live!"
As Rikku and Vegeta began shouting at each other, Goku just floated there awkwardly. This really reminded him of Vegeta and Bulma in his timeline, and he thought to himself,
"Some things never change, huh? Well, I guess that explains the whole saiyan-like woman thing."
During this argument, Goku had time to think about the situation. Rikku was a lot stronger than she should be at this point, especially since she was keeping up with his base form in Super saiyan 2. Her ki also felt odd. He could feel a slight pressure coming off of her. This made him curious, so he told Vegeta,
"I'm gonna fight her. Stay out of it."
Vegeta, enraged by this, muttered,
"Why you….."
He powered up to super saiyan 2 and tried to charge at Goku, but was suddenly blown back by a huge gust of wind. It was RIkku, who had begun powering up, shaking the entire planet. Her hair grew out even more than it already had, her body bulked up slightly, and her eyebrows vanished. Once the transformation was complete, Rikku floated in place, now a super saiyan 3. Utterly shocked, Trunks said to himself,
"What the hell is that?!"
Piccolo, who had heard what was going on, then told Trunks from behind him,
"That's super saiyan 3. A lot's happened in this timeline since you left."
A shocked Trunks asked,
"Piccolo?! When did you get here?"
"I sensed your energy and came to see what was going on. I heard everything."
Back in the air, Goku smirked. If this was Rikku's full power, he could actually have some fun here. Super saiyan would be a bit overkill, but he did have a technique that would make this battle fun. The problem was, he hadn't used this technique in decades. Luckily he was powerful enough to take it, and all he had to do was remember the correct method of controlling it.
Tensing up, Goku's body began to steam as small crackles of electricity formed around him. Luckily this wasn't anywhere near as painful as the last time he had pulled this off. Rikku cocked her head to the side in confusion at this sight, but realization soon dawned upon her. Goku then yelled,
"Kaioken times 3!"
A violent red aura engulfed Goku, and sure enough he could feel virtually no strain from the power. He could probably hold this even longer than RIkku could hold super saiyan 3. Rikku asked him,
"How in the...?!"
Goku simply told her,
"Trust me, we're more similar than you think."
Goku then got into his fighting stance, and rushed at Rikku with a flurry of blows. The two began swapping blows, each taking the same amount of hits they dished out. Rikku tried hitting Goku with a right kick, only for her counterpart to block it and respond with a punch to her cheek.
The two then collided punches 4 times, ending with a double punch to the cheek. Everyone looked on in shock, wondering who would win out. However, the two saiyans ended simply flying back and recuperating, taking the chance to review their opponent's strength. Meanwhile, Beerus and Whis had been watching the entire fight from a distance.
Beerus had gotten bored and so ordered Shin to take him to Earth. Shin had of course agreed. Whis told Beerus,
"The power emanating from this saiyan is considerable, sir."
Beerus replied,
"Indeed. And it's interesting too. It feels like Rikku but not Rikku. I've never felt an energy quite like this before."
The two parallel universe saiyan counterparts continued having a stare off until Rikku said,
"You're pretty strong for not having god ki. If you were someone else, you'd make a great sparring partner. But it's time to end this."
"End this? I'm just getting warmed up."
"Heh. me too."
RIkku then began powering up, but her hair shrank back to its original size and her aura retracted into her body. Her body was then engulfed by a fiery red aura, and once it cleared her hair had become red, her body was slightly slimmer than in base, and she looked a good bit younger. Goku was shocked by this transformation, thinking,
"What the hell is that?! I…I can't sense her energy!"
Rikku told him,
"This is Super saiyan God. Get ready."
Goku was surprised. Super Saiyan God? He remembered reading something about that in the Namekian book of Legends during his time in the dragon realm. How it could be created by 5 pure-hearted saiyans pouring their power into another. He thought to himself,
"This must be one of those changes Zeno said would happen. This might be a bit of an issue."
Goku got into a stance as his hair began to stand on end. A golden aura burst to life around him, and as he glared at Rikku, his eyes suddenly turned green as his hair turned gold. Rikku's eyes narrowed at the sight of this, and the two charged at each other. After a violent exchange of blows, it was clear that Rikku held the advantage.
She landed 3 hits to Goku's face and then landed a powerful hit on his stomach, causing him to cough up blood. Rikku attempted to launch another punch, but Goku managed to catch it and powered up to super saiyan 2, afterwards throwing RIkku into a nearby rock formation. As this was happening, the portal Goku had arrived from began to shoot out electricity, and the saiyan felt himself being pulled by something.
This distracted Goku for just a second, and that second was just enough for Rikku to kick him away. Goku quickly righted himself and launched a ki blast at her, which she managed to catch and throw into the air, but Goku took this chance to appear next to her and kick her in the back, sending her spiraling to the ground. The dust and winds caused by the impact caused Trunks's time machine to fall to the ground, making him say in panic,
"Careful! Not the time machine!"
As Goku heard Trunks say this and turned to him, Rikku took this split second to fly up and punch him in the stomach, winding him considerably and causing him to hack up spit. Rikku then launched another punch at him, but Goku flared his super saiyan 2 aura and delivered his own punch. The two's fists collided and they began struggling, both saiyans putting in everything they had to overpower the other.
However, as they clashed, Goku's time ring began to glow. As it did, the portal began to crackle. Eventually, a brilliant white light exuded from Goku's time ring, and the saiyan began getting pulled towards the portal. Shocked and confused, Rikku powered down to base and asked to herself,
"Whoa, what's happening to him?"
As an equally confused Goku struggled against the time portal's pull, he asked Zamasu,
"What the heck's going on?!"
Zamasu, equally shocked, replied,
"The distortion in space-time must be dissipating, it's going back to normal!"
Goku, not exactly knowing what that meant but knowing he was being pulled, looked at Trunks's time machine. If he couldn't win here, he could at least buy himself some time. He then held out his hand and fired a ki blast at the time machine, obliterating it. Everyone was shocked, with Trunks yelling,
"How could you?!"
Goku was then pulled by the time portal back into the future timeline, leaving everyone in the present extremely confused.
Goku rematerialized in the future timeline, and after recollecting himself, he yelled at Zamasu,
"Why didn't you tell me there was a time limit to this thing?!"
Zamasu replied,
"I'm as surprised as you are. But it doesn't matter. We've stranded Trunks in the past forever, and the girl and his nephew are small fries compared to him. We've won! There is no one left in this world who can resist you!"
"Don't be so sure, Zamasu. If their Bulma's anything like mine, I'm sure she'll be able to find a way to fix it. In the meantime, I'm going to recuperate and prepare."
Goku then flew off, while Zamasu continued to tell him to finish off the humans. Goku didn't care at the moment however. All he could think about was fighting Rikku again. As much as looking at her enraged him, he'd be lying if he said he wasn't excited to fight her again.
Meanwhile, near the spot where the time machine had departed to the past, the Pan from the future timeline lay, seemingly dead. However, her arm began to twitch…
Power scale
Rikku: 1
Goku: 125
Trunks: 0.75
SSJ4 multiplier: 400,000
SSJ God multiplier (Non-ritual): 100,000
SSJ God Rikku (Supressed against SSJ Goku): 10,000