So basically Dark Powers could be related to Cthulhu. Hence the Fear effect being a key feature.
More or less. The darkness powers certainly seem to rely on that idea, where even "a glimpse into the terrifying netherworld renders [enemies] held." So for game mechanics, you get fears and holds as a result, and resistance to psionics.
Also: "The Netherworld is one scary place, and with but a touch, you can give your enemy a glimpse into this dark world. This will cause them to helplessly tremble in Fear."
It is worth noting that Warshades also do Negative Energy damage to their foes, so Negative Energy is not, by itself, only associated with the Netherworld. I'm not sure if that was conceptually intended to be the same type of damage, or if it was convenient for Warshades, who manipulate "dark energy," to just use the existing Negative Energy damage type. I would lean towards it being a matter of convenience, because the implications of Kheldians being able to tap into the Netherworld get rather interesting (although the whole idea of using souls, or energy from souls, is not necessarily incompatible between the two power sets (darkness and Kheldian), I rather prefer to leave them separate).
What's even more interesting is the wording of Demon Summoning, which says you are able to: "Conjure demons from the depths of the netherworld and beyond." And
beyond?? That's VERY interesting. There's also a number of references to hellfire, unholy energies, and "the Abyss." Akarist, in Cadao Kestrel's arc, does talk about Hell, and demons being from there, but it is one thing to have an Oranbegan talk of Hell, and quite another to have player character powers derived from it.
But, of course, the question becomes: is the Netherworld actually "Hell?" Given the answers to AMA questions in my previous post, I would say that it is not. Yes, dead souls go there, but as the purpose of the Drudges in Night Ward shows, they are not meant to stay there. And Baron Zoria mentions that many of the original human Circle of Thorns had their souls "flung to the void." So there are other places than the Netherworld for souls to go.
However, given the terrifying nature of the Netherworld, and the fact that there are native beings of some sort, generally malevolent, I would say that it more or less qualifies as what people of the CoH universe would understand as "Hell." It also seems to me that souls are used as currency there, or taken to be used in order to empower various Netherworld beings. So not only is it a place of madness and terror, but your literal very soul is all but powerless there, and often subject to the whims of the denizens of the Netherworld. But it is not a Hell born of a particular religious paradigm, in the world of CoH - it is merely a stopping point for souls before they move on to... somewhere else.... which is presumably left undefined to allow multiple religions to flourish without angering zealous players.
Of course, the Dimensionless and the nature of the universe being revealed do sort of put the lie to this particular ambiguous and wishy washy "where do souls go?" question. Eventually, the nature of the universe would have been explored, via the Incarnate story line (see Lore AMA for more). Furthermore, the "Angels" in game were Dimensionless (
http://paragonwiki.com/wiki/Lore_AMA/Sorted#137) and spoke of the heavens, and there is even one fallen angel whose description speaks directly of "divinity:"
http://paragonwiki.com/wiki/Dark_SabaothThis all becomes very interesting when you read Lore AMA 292:
http://paragonwiki.com/wiki/Lore_AMA/Sorted#292 This is pretty much an overview of what the "true" nature of the CoH cosmology would have been described as. There is enough leeway in here to fit our own religions in (arguably) but it doesn't mention souls... but I would argue that answer 59 (
http://paragonwiki.com/wiki/Lore_AMA/Sorted#59) gives us a glimpse into that. It is already clear, given the nature of demons to use souls as power sources, and some other powers in game, that souls have power. It could very well be that souls are the manifestation of power that all life generates, as mentioned in 59, and that the Netherworld just stores them before they get reabsorbed into Wells, or used to summon demons, or brought back by necromancy, or used for darkness powers...
Now, I should note that not all darkness powers use souls directly (in fact, only Soul Mastery directly mentions it, as far as I can tell). Rather, they use the power of the Netherworld itself, which is only the place where souls go. Sure, you can use souls, but I'm sure that heroic characters wouldn't want to do that.
...none of which really necessarily applies to the original question here. I should also note that this is pretty much all just my personal take on things, as I interpret the game and Lore AMA. Even with the AMA, which may be discounted by some, there just isn't enough hard evidence for anything involving the Netherworld or souls or demons to really truly confirm what I'm saying.
