Darkness is easily tied to every resource really aside from stamina and equilibrium.
Paradox - Space stuff
Mana - Necromancy
Vim - Because it's dark...
Celestial - Because the sky can be dark...
Psi - Because you hate yourself
Hate - Because I hate you
Keep in mind it's kinda a hard resource though. A lot of monsters resist it or are outright immune.
(And just wanted to say, diseases in ToME are not natural. Presumably all natural diseases are inconsequential for the player character and he/she only needs to deal with magical ones.)
Death isn't directly linked to anything but souls. Even vim is powered by draining life force from victims, which may CAUSE death, but isn't death-dependent (as evidenced by skills that drain vim without killing). Hate may work well mechanically, but by lore it is more linked to mindpower than spellpower.
Also, I said I wanted the class linked to darkness, but what I really meant was the darkness of the grave, thus really meaning death. Space isn't associated with death, even if it is associated with darkness. I guess the negative celestial energy goes the same way. I also wanted this to appear as an inherent power, not something the user learned to master like mana or vim or celestial.
Sure, the flu isn't going to kill anyone in combat time - but is there any reason that you couldn't supercharge an existing natural disease with equilibrium?
So... if we're not doing Negative Energy, Hate has some possibilities. Resource of the Afflicted, it's a power source based in coming out the other side of bad, bad magics, and it's the sort of thing that erupts spontaneously. Hate isn't something that you develop - it's something that happens to you. Hate's great for melee attacks - you could easily steal a tree or two off the Cursed, for example - but switches to Mindpower when used at ranged, which we'd prefer to avoid. Swap Undead Strength and Death Blade to Hate-based trees, and Hellrime and Black Grave to soul-based.
Also, toss something in where Hate decays rapidly when there are no enemies in your aura, but far slower when you are engaged. The really powerful melee attacks aren't limited by the rarity of souls, then, they're limited by the fact that you have to build up to them in combat. Vampiric Blows becomes free to sustain (as all Hate sustains are) but costs you hate with every hit (and cranks the HP drain down a bit). Might make sense to have it instead crank up both drain percentage and drain likelihood - let it stack with the gear that does the same. On the flip side, Soulchilling Blade becomes your third 3-soul sustain.
-----------------
Tactical concern about Magic Dead as-is: it synergizes way too well with itself at the 5 level. Specifically, the major issue with Blurred Mortality is that you don't know when you're going to keel over. With Magic Dead 5, you don't have to worry about it. You fight until you switch into blurred mortality, you fight until you kick over back into normal HP, and then you hit your teleport rune (or possibly your shield rune and then your teleport rune). As long as they don't take you from 30% HP to 0% HP in that turn (and you don't teleport anywhere unfortunate) you're pretty much safe. Certainly, it makes vault-hunting after you've cleared a level a lot less dangerous.
Suggestions/thoughts:
- get rid of the 30% life boost for 5. 10%/soul is plenty - and if you die with no souls... so much the worse for you. This whole "come back from the dead" thing is bonus anyway.
- Instead of having it be 10% life per soul, possibly make it a 10% chance per soul of coming back at full life. Makes it a little less dependable (particularly to people who go heavy on the sustains) but hey - there's always the Eidolon, right?
- If you don't like the 10% chance instead of 10% life idea, but don't mind dropping the base 30% health, possibly have Magic Dead have a secondary effect - whenever you're in the Blurred Mortality state, every hit on you has a chance of causing one of your souls to detonante, doing significant damage to your attacker but losing you a soul. HIgher levels of the skill would have it dealing more damage. Again, makes it a bit dicier for people who are running high on sustains and/or low on souls, but not as a pure loss.
I had originally intended the 30% base for Magic Dead as something that would allow someone full of souls (only 7 under Magic Dead alone) to resurrect with 100% HP, but I see your point. It's more desirable to leave a bare-edge resurrection at bare edge than to leave a full-precautions resurrection at full HP.
I like the 'unstable souls' idea for Magic Dead, but it may make the skill a little too complex. Reduce max souls, effectively boost max HP, chance for resurrection, AND chance for damage that costs you HP on resurrection? Maybe, but it's a lot to consider.
As for the Hate option, on further thought, I wouldn't have a problem with this class being curse-linked, with the powers being mind-based, but I'd still like the physical powers to be based on souls. My idea for the character is that souls are it's life-power, the thing that gives it movement. Souls feed the character through the magic that bound the first soul to life again. The hate-fed curse may allow it to draw creatures closer to death, or link them to the grave, but those are non-physical and probably ranged options. This class could end up operating something like a cross between a necromancer, a cursed, and a doomed. I'd still like hate to be powered by the necrotic aura, though, and not by enemies being killed or doing damage to the character. Souls are linked to kills, so linking another source to it as well seems like a bad idea. All in all, though, hate really fits with the idea of the powers being innate and not learned, and a link to the cursed classes really works for this forced-from-the-grave class.
I could see hate being linked to aura and/or damage, but I'd argue that there should be ways to get it other than just kills/souls - part of the point of including a non-soul resource was to get a resource that didn't run out because you ran out of dinky things to kill.
The point of the unstable souls thign wasn't to reduce the HP that you have when you go under - it was that if you're running all three sustains, then any hit the enemy throws at you could be the one that strips that last soul from you and takes away your resurrection altogether.
Beyond that, I don't really know how hate works by default (I've played Cursed but not Doomed). so I don't know how much of the behavior of Hate is class-specific and how much is intrinsic to the resource.
If you want to make the Hate be mindpower, largely at range, and the souls be phys power, largely at melee that could be interesting. I just wanted to be sure that the player wouldn't be stuck having to push magic power, phys power, *and* mindpower. It would mean that the base stats were suddenly Strength and Will, so that could be interesting too.
For cursed, hate is gathered by killing or by being hit really hard, if I remember correctly. I think doomed can gain hate the same way, but they can also 'feed' on a target at range to gain hate. The way they use hate, this is very important. Even for cursed, gaining hate that way would be quite useful. For this class, I'm thinking we could bar the first two (damage and killing) the way arcane blades don't regenerate mana normally. Instead, the Death Knight would gain hate by enemies entering his death aura. Since almost all kills would probably be done at melee range, or just barely outside of it, a large aura for gathering souls isn't really useful. Gathering hate from even just 4 tiles away, though, would be quite useful.
Cursed also gain hate by having particularly powerful enemies enter their gloom, and for doing particularly impressive high-damage hits.
Possibly leave them the normal "deal damage/take damage/kill" boosts, give them a bit of hate every turn for enemies in the aura... and have their Hate plummet much faster than normal when enemies are not in the aura. When they're in a fight, particularly a fight with a number of enemies, they'll have hate to burn. Opening moves, however, would pretty much be souls or nothing.
I just had an interesting idea for replacing the necromancer-based blurred mortality talent. What if, instead of giving you negative life ability, instead it was the following:
Living Death (sustained, -3 souls max): Every heavy blow brings you closer to the death that feeds your life. Any damage that deals more than X% of your max HP will be followed on the same turn by healing of Y% of the damage dealt. Because this healing is applied after the damage is applied, damage that brings you to 0 HP will still kill you.
This talent would, first and foremost, reduce the chance of instakills or the effects of damage spikes, which tend to be the largest threat to most characters. Maybe less for melee-focused characters who tend to invest more in CON. Also, to consider, increasing max HP makes the effects of this talent less common. Is this a good idea? Too powerful? Too weak?
Not sure how good an idea it is, though I will note that how powerful it is obviously depends on the values of X and Y. To take (unreasonably) extreme cases, if taking X% of your max HP healed 80%, that would probably be overpowered! Likewise, if it took 40% of your max HP to heal, say, 10%, then that's a rather weak talent.
I was thinking more along the lines of (30/25/20/15/10)% of your HP damaged healing (10/20/30/40/50)% of the damage dealt, but that's just a guestimate. I'm really wondering if there is ANY level that would be evenly balanced, or if it would simply switch instantly from too weak to too powerful depending on the numbers used.