Interesting stuff that I am going to shamelessly steal.
Given the focus on the rivers of death, Abyssal Sail is probably a lot more useful, right?
Also, is distance the same between Creation and the Underworld? By which, say there are two Shadowlands fifty miles apart in Creation, would they be roughly fifty miles apart in the Underworld too or would you be able to use the Rivers like a Sidereal can use the Yu-Shan gates?
Or would something like that be more what you invest in Abyssal Sail and/or Necromancy for?
Close to Creation, the distances are what people associate as the distances based on how much they think of the place. So if people think of a place as being closer than it really is, it'll be nearer, while if they think of it rarely, it'll be further.
Deeper down, things are more surreal - not least because when you get down to Shogunate places, Creation had mass transit systems and trains and stuff, so places were closer together in terms of time. And as the domains move up and down and wage war on each other and conquer each other, distance warps, because it's more based on how close the Dead think the domains are than the mortals.
So, yes, a good ferryman can follow a path between two shallow domains which is a lot shorter than the distance between the Creation places, but that means they'll probably have to head down deeper towards the Shogunate and fight the current on the way up - and it's less safe the deeper you get. Which is why you need a good ferryman. The very best ferrymen can skirt the edges of the Labyrinth and take advantage of the way time and space breaks down down there to cross distances very very quickly - albeit at the cost of having to fight off Greater Dead and undergoing a gothy version of that bit from the old Charlie and the Chocolate Factory film and the teeeeeeny risk of crewmembers succumbing to Whispers and cutting all the sails. And yes, you can use Cysts for "gravitational slingshots" if you know what you're doing.
Try not to get caught in a waterfall into the Labyrinth.
Oh neat, so they come prepackaged with the ability to go "Behold my True Form and Despair!" without having to get B.O.S.S.
Yep. Certainly a handy trait, though it wasn't the design intention for it.
It's simply that hun ghosts get less and less human as they raise in Enlightenment, because they're becoming less "human ghost" and more "Underworld creature". Because the human hun is a pale, crippled reflection of the person, unlike the po (which is the source of all the vitality and the seat of power). Therefore to raise their Enlightenment, ghosts need to find another source of power to sup on. Cult is one source, and that lets them remain basically human, but that has its limits - and very few ghosts would ever get to benefit from high Cult, even in an ancestor-worshipping society. Which means that the Deathlords, the ones who have ventured down to the tombs of the Neverborn and supped on their power, are very inhuman indeed.
(If their true form isn't very inhuman, that means their mind must have been horribly warped - but the fact that their true form is inhuman
doesn't mean that their mind isn't very warped.)