Riley groaned for a moment before using Instant Transmission to teleport to her second-to-last planetary destination. Every single Core girl hated these last two planets.
The Grey and the Black planets.
Once you got to these planets, very little light from the Core's sun was traveling far enough to reach them. They were out of the goldilocks zone that life could technically survive in, to an even worse degree than the Red planet. That meant that, from space at least, they both looked pretty similar. Freezing lumps of ice. Nothing more, nothing less. Very little heat touched the surface of the planets, which meant that the surface temperatures averaged dozens of degrees below freezing in the summer. It was awful.
But that was only on the surface, at least on the Grey world.
Every planet that could sustain life needed a magnetic field and atmosphere. That required a spinning core composed of dense magma. That core also created heat, deep beneath the surface of the planet.
On the Grey planet, the heat created by the planet's core was vital for the Grey Saibamen's survival. you see, the surface of the planet was actually composed of a thick sheet of ice. Beneath that ice was an even thicker layer of water. On top of their normal duties, the girls responsible for reporting on the Grey Saibamen also had the duty of checking the composition and density of the icy surface, as well as the composition of the core and magnetic field. Without the girls ensuring that the planet stayed active, it would (maybe only in a billion years, but still) eventually cool down and become unsuitable for sustaining life.
'hmm. Almost three millimeters less ice than the last report stated, across the board. That's not good.' Riley noted. Part of the reason that the Grey planet was warm enough to sustain life was because the planet's atmosphere lost pressure in the winter, when the surface was further from the sun, allowing the icy surface of the planet to temporarily sublimate into a gas, a chemical process that generated a small amount of heat, especially on such a large scale. That's a large part of why the ocean in the interior wasn't as cold as the planet's surface. Three millimeters of ice loss in the single week since the previous report was a pretty fast loss. Riley made a note to have one of the girls back on the Core do some math to figure out how long the planet would be able to last without their interference, so that they can figure out exactly when to add to the ice. The first few years (On the grey planet, one year was almost 150 Earth years) would be a huge pain for the girls as far as this planet went.
'This planet really is a work of art, though. That documentary on Pluto that Mistress watched before her death really came in handy.' Riley thought to herself, annoyed that she couldn't voice her thoughts out loud since she was currently underwater.
'Time to check out the Grey's civilization. It'll be interesting to see how an underwater city survives.'
Riley didn't see much need to use Instant Transmission to get to the aquatic Saibamen's city, since she was already so close to it, so she swam instead. With her Core Girl body, she didn't need to breathe, so she didn't feel any physical discomfort from staying underwater for long, but the planet was definitely not meant for humans to survive in. No light, and fairly intense constant pressures. Such a pain. But all of her negativity faded in an instant when the city came into her detection range.
'Amazing.' She almost voiced it out loud, but getting water in her mouth would've been such a pain, so she stopped herself.
The World Tree was completely underwater, and that had an interesting effect on it. It made the tree grow more than it had on the other planets. In hindsight, it made sense. The pressures underwater were intense, but since they weren't aboveground, gravity was pretty well cancelled out by buoyancy. As a result, the World Tree's branches spread for miles in every direction, beyond the limits of the city that the aquatic Saibamen had managed to create on the rocky seafloor.
As for the Saibamen themselves, their powers were pretty average, all things considered. They were stronger than the mental Saibamen, specifically the White and Blue ones, but their average 5,000 power level paled in comparison to the Yellow and Red variants. They had pretty incredible defense to make up for it, probably due to the underwater pressures, but their offensive power was little to worthless in value, and the first generation's bodies were rather unsuited for swimming.
To top it off, the first generation was also pretty clumsy, as their eyesight was almost totally useless with almost no light. They'd managed to develop energy detection techniques similar to echolocation to make up for it, but they weren't very fast, since they needed to constantly use those techniques in daily life. As if to make up for it, they pretty much only used their energy for that one technique, and had never learned to use ki to enhance their physical strength like the other variants. It was rather interesting how that worked.
The second generation was an improvement to the first generation pretty much across the board, though. Their skin had smoothed out, becoming silky like a dolphin's, and their feet had turned into flippers. In a clear display of the impressive nature of the World Tree fruit's effect on the Saibamen's evolutionary line, their eyesight had undergone an incredible growth, rather than reduction. Normally, in such dark areas, species would grow to not need their sight, but these guys had grown incredible night vision instead.
As for their growth rates, the second generation grew rather quickly comparatively. They already looked like five year olds. It was likely that, due to the environment, they'd always grow faster than humans, which was a boon. As for the second generation's power level, in a similar fashion as the yellows, their power levels on average were almost exactly equal to their parents' already. They'd likely end up topping out at around 50,000. Not as strong as the winged or the reds, but their defense would make them pretty useful in battle.