Conceptual Balance Mod 1.84

[Executor]

I'm also in favor of rebalanced blood prices and bringing back SDRs. These last few posts sum up perfectly why removing them was a bad idea.

As for the blood prices, I think the main problems are vampire lords. Frankly, any blood summon compared to them is hardly worth it. I find them completely OP, I'd increase their price by say 1/3, to 99.
With enough vampires lords you sort of become unconquerable, and with the current price of 66 you can very easily summon 2 to 3 of them a turn meaning that I pity the fool trying to go up against a few dozen vampire lords, probably backed up by a few hundred vampires as well on top of anything that nation might have besides blood.
Also, bone fiends are still OP even with 7 for 3 slaves. It's not really hard to completely trample a nations with them early unless they have powerful archers. Instead of lowering their number I'd suggest an increase in price, say 5.
With their current price you can mass hundreds of them pretty fast even in early game.

[Psycho]

Vampire lords are terribly overpowered at 66 blood slaves. I should know, I've been using them in almost every of my games. The completely useless succubus costs 66 blood slaves FFS.

All devils, both lesser and greater are underpriced as well. The greater ones at least all have limited numbers, so they're not as overpowered as vampire lords. Bone fiends are especially OP among devils with nations with non-capital-only BD mages.

The remaining blood spells are pretty much ok. Maybe dark vines and disease demons could be a bit more expensive, but that's about it.