Disclaimer: I don't own the Dragon Ball franchise or it's related concepts and characters, but Akira Toriyama and his affiliates do.
[ADI]
A Demonic Invasion
[ADI]
King Moai's royal palace, Planet Arlia, Age 761
In the years since he seized control of Arlia, the tyrannical King Moai felt fear and desperation for the first time in a long time, even as he tried to hide it well. In the short amount of time since the attack began, the so called Dark Empire had devastated Arlia's planetary defenses with the unsurprising help of Atla and his loyalists. Although Moai tried to intimidate the Arlian people that the Demons were manipulating them to take better control of the planet, his detractors apparently hated him more than the thought of foreign occupation and were finally laying siege to Moai's last stronghold. He had considered threatening Lemlia to get Atla to pull his punches away from the attack but abandoned that thought in spite of his forcibly coronated Queen looking hopeful at the thought of her returning freedom.
"My King, the Demons have halted their attack!" One of the guards reported as Moai and Lemlia resided in the palace war room.
The worrisome atmosphere remained in place for less than minute until a part of the ceiling collapsed not far from where Moai and Lemlia stood in anticipation. From the unexpected entrance, a terrifying humanoid alien with a primate's tail belted around his waist killed Moai's guards one by one until finally, he was left to grovel.
"No, wait!" He begged on his legs. "Please don't kill me, General Kakarot! I can be of use to you and your Queen!"
The alien in service to the Dark Empire merely smirked at Moai's cowardice before replying. "I doubt it." And with his hand put forward to charge an energy attack, killed the Arlian dictator once and for all.
"Is it over?" Lemlia brought herself to ask in a slightly intimidated tone of voice.
Turning to her with a stern gaze, Kakarot answered. "Your actual husband has agreed for your planet to host a military base in exchange for protection from any unwanted enemies and natural disasters. I trust you can abide by our agreements as well, your Highness?"
"Yes, of course, General." Lemlia forced herself to respond before adding in a genuinely grateful tone. "It will be Arlia's pleasure to aid its new heroes of the Dark Empire."
Kakarot couldn't restrain a small smile at the statement as it wasn't every day that a Demon, or a Saiyan would be referred to as heroic.
[ADI]
The Demon Realm
Returning back to the Demon Realm, Kakarot bowed in respect towards Towa who was awaiting him with unusual enthusiasm.
"Rise up, darling." Towa said in a flirtatious manner. "We have much to plan for our eventual confrontation with Frieza."
Kakarot smirked broadly in eagerness as he rose on his feet. "Isn't that the truth?" He rhetorically asked before Towa prompted a kiss between them.
[ADI]
Played this out in some similar manner to the opening of the second to last episode of Superman: The Animated Series, if that's alright. As much as I'd like to play out a Frieza Force Goku/Kakarot, that faction didn't seem to have girls in it until Dragon Ball Fusions by default of some female characters being of the same race of Frieza's advisors and the Ginyu Force, so you know. And I'm not all that big on stories that place too much emphasis on original characters unless they are necessary. No offense to any and all fans of OCs and self-inserts intended, though.
Speaking of available female characters, a while back on DeviantArt, AsylusGoji91 asked me what I thought about the Universe 6 female Saiyans, which I assumed meant that they'd like me to do one-shots about them. However, I'm kind of iffy because by the time of Super's finale, Kale and Caulifla seem to be teens compared to Goku who would be in his forties and his sons are kind of dubious depending on their own ages which leaves Cabba by default. But, I have considered that all the Dragon Ball universes don't share the same "time cycle", so as far as I know, U6 might move slower compared to U7, if you know what I mean. I'm just wondering.
I actually recently had a thought of Goku ending up trapped in the Demon Realm at the end of the original anime episode Goku Goes to Demon Land in a what if situation which forces him to climb out of the gutter in that wicked plane of existence to the top of the food chain one way or another as the regular universe develops without him a la Turbulence. If three or so Namekians from Fusions could pull it off, I'm sure Goku would be the Demon Emperor. It's just a thought, everybody can do with it as they wish, but I'd pleased if it did become a story like A Toxic Empire was inspired by my One Piece One-shot Venomous Playground. Just be sure to give a shout out to me.