Mount Chaining, if memory serves, is a blood site which offers a 40% discount on... conjuration, IIRC. The minor blood sites tend to give just unrest, or a little gold; but some do offer devils, discounts, et al. Damned Merchant is convenient, although the impact is minor if you've got even a couple of teams of blood hunters.
Turn off auto-tax, drop taxes to 0, use a couple of B1+ hunters with Sanguine Dousing Rods, move 'em along when pop drops a lot or make 'em pause when there's high unrest.
Blood got a couple of nice new high-level combat spells, and some high level ritual eeeeeeeevil (Horror Seed
), and there are some fun items to forge... but it's still a summoning school at heart.