(Author's Note: in this chapter, Gohan calls Trunks "little brother" because Gohan sees Trunks as a younger sibling of sorts.)
3 Years Later
Trunks had done it- he had arrived back from the past and he had destroyed both 17 and 18 effortlessly. Finally, Gohan hoped, they could enjoy some peace for a change. But first, there was something else he had to do. So he silently followed Trunks back to Capsule Corp., and after witnessing Trunks destroy a strange bug-like creature named Cell, Gohan followed Trunks into the Capsule Corp. building.
Trunks was talking to his mother, Bulma, and both of them were joyful that now, they could finally enjoy some peace. "Trunks, I'm so proud of you!" Bulma exclaimed. Another voice spoke up from behind Trunks: "You took the words right out of my mouth, Bulma." Bulma gasped and Trunks whirled around, his fists raised- and then he gasped too. "What- Wait- Is it r-really you?!" Trunks exclaimed. Gohan smiled. "Hey, little brother. It's been a while."
A Few Years Later
Much to Gohan's delight and surprise, Trunks achieved Super Saiyan 2. Much to Gohan's worry, though, Trunks insisted on stopping there, confident that he could handle whatever foes came next with Super Saiyan 2 alone. Gohan, on the other hand, kept training, eventually feeling that he was on the edge of a new form after a few years of hard work. After fending off a strange alien wizard named Babidi and his servant Dabura thanks to some training from a god named the Supreme Kai and the Supreme Kai's servant Kibito, Gohan and Trunks were both looking forward to peace at last. But a few years after that incident, once again fate denied them peace. Because on a sunny day over a city, a strange portal appeared, and out came a figure with Goku's face and body.
He was wearing a light black martial arts uniform with a red sash, along with dark black sleeves and loose martial arts pants. He also had on white martial artist boots, too, and on his left ear there was a Potara earring, just like the ones the Supreme Kais and their attendants wore. (Supreme Kai had informed Gohan of those earrings... and what they were capable of.) The figure spoke in Goku's voice, only it was a bit more rough and stern than the voice Gohan knew: "Hear me, disgusting mortals: I am Goku. And now, I will annihilate you Earthlings in the name of justice." He charged up a Kamehameha, only instead of being blue, it was a deep purple color. Then he fired it down on the city and in an instant, the entire place was gone, along with all the people. In only one hour, he wiped out three more cities. The stranger hovered over the burning remains of what was once a bustling town, with a smile on his face. He suddenly noticed something and looked up as a blur of yellow light crashed into him. The figure blocked the attack and stopped himself in midair, and the light cleared to reveal Gohan in his Super Saiyan form. Trunks as a Super Saiyan was on the way as well. Gohan got a good look at the enemy's face and his eyes widened.
"Dad? Is it really you? Wait, no, it can't be. You're not my father! You can't be him! Who are you?!" The stranger chuckled. "Is that any way to address a god?" Gohan snorted. "Some god. What kind of god wipes out half a continent?! Wait, actually, I don't know and I don't care. God or not, this world is under my protection, and I won't let you do whatever you want!" Suddenly, Trunks arrived, grabbing the hilt of his sword and getting ready to fight. "And I won't, either!" he added. They both prepared to face off against the fake Goku.

STAI LEGGENDO
Survival - A Dragon Ball Fanfiction
FanfictionWhat if Future Gohan survived his fight with the androids and eventually fought against Goku Black and Zamasu with Vegeta, Goku, and Future Trunks? Here's what I think would happen! Enjoy!