"That's right, Father! This is the most precious gift I could offer you: a spaceship capable of faster-than-light travel."
Russ glanced at the Emperor with a touch of pride.
'So you have this side to you too, my dear father? I always thought you'd remain perfectly unruffled, no matter what happened!
'The vision I'd seen was true!'
The Emperor's fascination with FTL engines was beyond description.
"Is this really an FTL engine? Where did you find it? Where did you get this ship, Russ?
"Judging by the comfort of this seat, and the exterior, the pilot should be almost exactly human,"
The Emperor began inspecting the small spaceship in detail.
Could a ship this small really make FTL jumps? But his own Primarch shouldn't be lying to him!
So how does its FTL engine work? What fuel does it use? The Emperor was full of curiosity about all of it.
"I stumbled across this ancient ship on Fenris, maybe it's the relic of some lost human civilization, or maybe it came from… who knows where!"
Russ replied.
'Don't ask me for details, I just found it by accident, I have no idea where it's really from. Anyway, it's a faster-than-light spaceship. Do you want it or not?'
The Emperor nodded, so long as it didn't come from the Warp, he didn't mind.
"Does it actually fly?" the Emperor asked.
"Of course it does! Here's the user manual, and the remote,"
Russ produced a controller that looked a lot like a calculator, and handed it to the Emperor, along with a small booklet.
Back when Axis first arrived, besides studying Fenrisian, he'd also translated the language from the Dragon Ball world, so the manual was already rendered into High Gothic.
The Emperor took the manual, studied it for a while, and quickly figured out how to operate the ship.
"I'm going to test the ship's performance myself. Take Russ back to rest.
Once I've finished testing, we'll talk about your reward."
With a wave of his hand, the Emperor shouldered the spherical ship and strode off.
Right now, the Emperor had no interest in anything else, he just wanted to verify that the FTL engine was real.
Two Custodes followed him, while the other two escorted Axis and Russ to a room to rest.
"Russ, do you really think the Emperor will believe that backstory about the ship?
"Saying it's an 'ancient ship' feels a bit forced," Axis asked after they'd returned to their room.
Saiyan ships were standard-issue from Frieza's army, all mass-produced, and none of them had been around for even ten years.
The Emperor would easily realise that.
"Hahaha, don't worry, little cub.
"My father doesn't care about details like that.
"As long as the ship can really do FTL, that's all that matters,"
Russ said, clapping Axis on the shoulder.
Some things don't need to be investigated too deeply.
As long as it's good for the Imperium and for humanity, that was good enough!
Axis nodded thoughtfully.
Russ was right: the ship's origins didn't matter; the important thing was that it could bring value to the Imperium, the Emperor, and humanity. That was enough.
"Get some rest, little cub. I need to check on my warriors. Stay in the room and don't wander off."
Russ patted Axis on the shoulder and left.
He was far busier than this little wolf cub; he had to look after his tribe's warriors and deal with his children, the Space Wolves Astartes.
Meanwhile, on the deck of the Imperator Somnium, the Emperor and his most loyal Custodian guards boarded a landing craft and, distancing themselves from the Imperial fleet, traveled to the far side of Fenris.
There, they opened the airlock of a small shuttle.
The Emperor's massive form shrank from over four meters to a brawny two meters tall, allowing him to sit inside the spherical ship.
He followed the manual's instructions and started up the eye-shaped vessel.
With a roar, the ship's faster-than-light engine ignited.
The craft shot away, trailing a red blaze, vanishing from the system in the blink of an eye.
Inside the cockpit, the Emperor looked through the crimson hatch, watching as the world outside flashed by.
From his perspective, everything outside slowed to a crawl, lights warping and shimmering around him.
In barely a dozen minutes, the eyeball-shaped ship had left Fenris far behind and reached a neighbouring planet.
After an hour, it was already near the system's gas giant. At this speed, in just seven or eight hours, it could exit the entire star system!
What kind of speed was this? It was thousand times the speed of light!
This was more than enough for short-range galactic travel.
Thousands of years ago, when human civilization was at its peak, humanity's technology had advanced to the extreme, examples were nano-robots which could devour a star in an instant.
Their power was beyond the imagination of present-day humans. But even then, they had never invented a truly stable FTL drive.
Simply exceeding the speed of light wasn't enough for interstellar travel.
Even ten or twenty times lightspeed was inadequate.
At a hundred times lightspeed, crossing the galaxy would still take millennia.
Warp travel, by contrast, could be completed in months, or, at its fastest, minutes. Of course, it could also take centuries… or result in total disappearance.
If you wanted to travel thousands, even tens of thousands, of light-years, a hundred times lightspeed was nothing compared to warp travel.
Peak humanity could create ships capable of several times lightspeed, but such speeds made galactic travel completely unrealistic.
That's why the Emperor never pursued FTL ships and instead focused on the Aeldari Webway.
But this little ship changed everything.
At a thousand times the speed of light, and with the Milky Way's diameter of 100,000 light-years, it would take a hundred years to cross the galaxy.
Even so, this was already vastly superior to warp travel.
For journeys under a thousand light-years, this ship would only need a year, and for even shorter distances, just a few months, comparable to warp navigation.
For anything within a thousand light-years, it could completely avoid the perils of the warp.
Though it couldn't entirely replace warp travel, it would dramatically improve the survival prospects of humanity.
[tl/n: so this speed is supported by the canon events in DB. I can give you a complete breakdown if you, my readers, desire!]