Quoting dihir, reply 62Resolyn, with 10 death shards , is practically untouchable by most units at a comparable stage in the game.
How, exactly? If your answer is the Wither spell, this isn't an advantage specific to Wraith blood - anyone becomes practically untouchable when you're casting Wither boosted by 10 Death Shards because it's -12 attack to every enemy unit on the battlefield. Wraiths don't get any bonuses from Death Shards that any other race wouldn't get.
Yes, wither spell and blood sigil spell. But the question I was answering here was "how can this work". It's kind of silly to ask multiple questions and then object that an answer to one question is not an answer to a different question, don't you think?
Once again, the biggest advantage is for the death magic users: this gives them a way of healing themselves that's more versatile than life drain (unlike the despair scroll, the spell is single target and takes an extra turn to cast. Wraiths are "weak troops, strong death magic users". But, when handled properly, those weak troops can still be quite strong.
Dirge of Ceresa, Corruption, Graveseal, and Infection are all from faction traits. Any other race would make use of these at least as well as Wraiths would. Dirge of Ceresa isn't good enough in my opinion that I'd want to ruin the power of all the spells I have outside of Death Magic until I get high level conclaves, and Corruption isn't that likely to help a lot in the early game. Graveseal and Infection are great, but don't depend at all on Death Shards - you can have any number of Death Shards from none to whatever the maximum possible number of shards is, but both Graveseal and Infection will perform just as well with zero Death Shards as with ten million Death Shards. These spells also don't particularly favor Wraiths over any other race.
Resoln also gets other spells. I believe I mentioned blood sigil and shadow bolt? And, for that matter, wither. Anyways, it's not any one thing in isolation, it's how everything works together. Dirge is amazing because it's instant and cover's the entire battle field. Because it's amazing, it's incredibly weak in its unaugmented form, but it can certainly be worth augmenting.
10 Death Shards and Blood Sigil makes anyone's militia practically invulnerable, because Blood Sigil casts Wither on the attacking army at the beginning of the battle. A 10 Death Shard Wither reduces the attack of every enemy unit on the battlefield by 12 points, and Wraiths get no more advantage out of it than any other race does. In fact, Blood Sigil is probably worse for Wraiths (and Amarians) than for any other race in the game, because it also casts Berserk on your units, which are somewhat lacking in the health department but now have to take damage every turn, and they're lacking enough in the armor department that even with the 10 Death Shard-powered Wither they might just still be taking about as much damage as they're dealing, depending on the weapons and armors being used on each side, and might possibly be taking more since militia tends to have crappy weapons.
Militia usually hit hard in the early game (which is the main time when you have to use them without backup). They are also disposable, I was just using them for an example. You are right of course that this does not win all battles. And, of course city militia alone does not equal city militia with demons and spiders backing them up. But again, it's not just this one thing in isolation. Resoln's dirge (once boosted properly) goes a long way towards making those death shards a viable strategy. Mind you, Oracle Ceresa is not tuned for this. I used impulsive and a few other traits.
Your 3 points of health from anything that died only matters if you actually have damage to heal.
Dirge of Ceresa (3 poison +1 per death shard for 10 turns, instant casting, 64 mana) is almost strictly worse than either Contagion (Air II + Death II, 2 poison +1 per death shard for 10 turns, 1 casting time, 18 mana) or Horrific Wail (Water II + Death II, 2*caster level damage on casting, 36 mana, 2 turn casting time). Horrific Wail is mostly better than Dirge because nothing is resistant or immune to the damage type dealt by Horrific Wail but many things (such as elementals, which are something that as Resoln I want magical help fighting against) are resistant or immune to poison damage, and Contagion is better because its base damage is only slightly worse and its mana cost is nearly four times less than that of Dirge of Ceresa, and a one-turn casting time isn't that bad.
I did not have those other spell casting schools, because I took too many traits. But instant cast is in my opinion a big deal. You need a lot of initiative before you can reliably pull off a multi-turn cast (without getting shot full of holes, counter spelled or rushed). Meanwhile, you can usually avoid monsters that you do not want to fight. (That's already how we deal with dragons and such in the early game.) And, you can use wither with some random infantry if you really need to deal with poison resistant monsters. (magic immune, however, require something like high level champions - they are painful when you are tailoring your strategy on death magic.)
I will agree though that mana is a big issue here: This is a power-hungry strategy. And it requires a lot of spell mastery to overcome resistances. But there are ways of dealing with both issues.
And, for that matter, mana management might be a good reason for not going all death shards - that 50 mana per shard is not subject to tactical cost reductions and there will be times when you need the mana from the shard and cannot afford the risk involved in lowering your mana pool to corrupt it.
How much would you be doing with a Fireball if you hadn't corrupted all your shards to Death Shards? Is having one or maybe two casters with a really good Dirge of Ceresa worth not having any good casters who don't have Death Magic?
Fireball only gets 9 squares. Dirge gets the entire field. And, of course, fireball is not instant cast.
Meanwhile, since this is a power hungry approach, you are not going to have the mana in the early game to many other casters.
But if you pick your battles properly, that's not too bad of an issue.
Cyndrum Demons are a type of shard-spawned unit that I do not like. They are completely reliant on health for their survival, and rely on killing things to grow more powerful (which, by the way, competes with Wraith Blood's rather crappy +3 health per kill, since the Cyndrum Demon has to make the killing blow for another demon to join the group).
If you neglect your death shards and protective spells, sure. But if you neglect your death shards you do not have to deal with those demons, do you?
How exactly does the power of Dirge of Ceresa benefit Wraith Blood, specifically? Keeping units alive by killing enemies before they can close the range might be more beneficial to Wraiths, whose units are easily killed, than to other races, but it doesn't mean that Wraith Blood is playing to the strengths of Resoln. Anyone would be benefited by killing off enemies before they can get close enough to deal damage.
Wraith blood + augmented dirge gets your caster a nice bit of health. (And if you are getting hit a lot, your caster is going to have options for health bonuses from level up.)
The wraith design is heavily tailored for death magic users - the biggest weakness of death magic is its lack of healing.
