[ano]

Death bless has some non-evident benefits. The first and the main one is that you will hardly be pushed by any sc in the early-mid game (maybe, in the late game as well). If anyone still wishes to use sc's against death-blessed nation, this sc will gather afflictions really fast if your troops have decent attack skill. And that's the point! for the best effect you should combine death bless with minor fire bless and the little jags will be able to hit even well-equipped sc's and nearly each hit will mean affliction.
Second benefit, is, of course battle magic.
Third one is the fact that it is really easy to protect an sc from fire but it is impossible to protect him from increased affliction chance.
Fourth one is what Natpy mentioned - death blessed units are more likely to cause disease than any other affliction. Not very pleasant indeed).

It was me who won a big game with W9D9 blessed EA mictlan a year ago or so. And as I wasn't satisfied with jags' and eagles' hitting capability, after that I added F4 and result was excellent. Mictlan sacreds do wonders and hit really hard with this +2 attack bonus.
So, I strongly think that most of you underestimate death bless. It is very good for good-stat sacreds you can amass.