The one change Dom2 really needs.....

[Zen]

Well you have to consider that the fatigue would still kill a goodly number of Mictlan priests, who are already pretty strapped for duty (research, blood hunting, forging ...).

But what it would allow you to do is use it to your advantage if you *needed* to without delving into that gulag that is the Gem Transfer screen for as long as nessecary.

[Yossar]

I never understood why blood sabbath cost so much (100) fatigue. That's the main reason I never used it. Even without requiring blood slaves, there's still going to be a lot of blood involved. The blood of the communion slaves. But it would be interesting for Mictlan to have fairly easy access to high level nature, astral, water, fire, and blood battlefield spells.

[Cohen]

Simply for default each gem cost for a battle spell == to 100 fatigue.

So Blood Magic isn't that used in battle magic because it costs not only slaves but a lot of fatigue.