I just downloaded the warlock mod and played a season and a half. No massacres or anything like Splint described so yay. Ghouls are ridiculously fast, especially since FPS is so high at the start. I've actually seen them almost teleport when moving. The ethereal portal actually seems a bit underpowered. You get valueless items for free. Whup de doo. It honestly feels like a less satisfiying version of the kobold leather upholstery workshop. Making furniture for free after the first 1-2 seasons, except the Ethereal portal doesn't work for making dining rooms or anything like that because 0 value. Giving the ethereal items normal wooden value would actually let you fill all those upperclass noble positions once you have a decently skilled engraver. Also I find the 3 gems per skill reactions a bit steep. Unless I happen to stumble across a HUGE gem vein I rarely get more then 10-12 gems per fort. Thats partly because I don't stripmine that much. If I decided to strip-mine for gems with mostly low-level miners, it'd take quite a while to get enough gems for the legendary engraver. And you need to upgrade skeleton skills to be able to manage work orders, update stockpile records, possibly go on raids(IDK if the overlord noble is the only one allowed to run those reactions), make weapons or armor or even maintain basic fortress morale. Maybe the cost should be reduced to two gems per 3 skillpoints? I also recall there being some mention of artificial gems being made from glass and ore dust. Was that implemented and if so what workshop would it be in?
TLDR: Warlock mode is decently fun, but its very difficult to get room value high.
EDIT: The default slade boulder throwing thing is NASTY. My necromancer was fetching a coyote corpse for butchering and he got interupted by a coyote. Then he slade bouldered him in the leg, making him give in to pain. The next shot was in the head. And the manual says its supposed to be armor piercing. I am seriously doubting the nessecity of having librararies to learn more advanced spells if the basic one kills or maims THIS easily.
EDIT X2 combo: On the other hand, firing deadly missiles from your hands means that when the warlocks go insane from the lack of room quality they'll carve a bloody(boney) swath through your fort.
EDIT X3 combo: Also the Restless walker things are really tough to kill. I spawned one out of curiosity. It currently has killed the entire animal population of the embark 4 times. His kills:
11 coyotes
7 giant dingoes
8 badgers
3 stranglers
Not bad for something spawned from one unit of meat. Now imagine 20 of them. **Evil smile**