Rebalance of 'The Dead'
Not having any growth at all is an interesting idea for a faction - I really like the Dead. That's the theory, at least, because balance-wise this faction leaves something to be desired - there are too many map generations that simply leave this faction with no choice but to... well, die. The Dead faction is extremely dependent upon either having an abundance of death shards or spawning right next to another faction so they have somebody to fight right from the start - both of these conditions are not the norm unless running non-standard world settings and so the Dead are looking at a difficult, uphill game by default.
In the luckiest setups, there will be one or two somewhat nearby death shards as well as city sites with at least one essence slot for Morrigan's Call, but even under such lucky conditions the Dead will grow at a snail's pace. The faction is clearly geared 100% towards warfare but that doesn't help if the game wasn't setup to overpopulate the map with players, meaning there are typically no other faction in the immediate vicinity to attack - the clock is ticking for the Dead and if they can't find somebody to assault very quickly to gain some population, they'll fall hopelessly behind.
My proposal for buffing the Dead and making them more viable on less populated map generations is to give them an alternative Scrying Pool: a spell version of it. Costing some 100-200 mana and so not being something to cast lightly it will permanently increase the essence yield of a city by one, being castable only once per city. This will help ensure the Dead have at least a slight chance to expand on the worst map generations where there are few or no nearby city sites with essence yields by enabling even cities that initially had no essence to have Morrigan's Call cast on them eventually.
Addtionally, I would give the Dead another spell version of something already in the game: The Resoln's 'Corruption' spell. It would essentially be the same spell but would cost much more (~200 mana) and be included as part of the 'Undead' trait package rather than the 'Death Worship' one. You might think this would be overpowering but given the extremely high mana cost of all these spells it should prevent the Dead from snowballing too well - it would still be preferable to war with another faction for population but with this option at least the Dead don't automatically lose when such is not possible. It would also be interesting to further increase the Dead's focus on mana generation in this way.