[Teraswaerto]

There are big differences between the damage increase you get from Blood, Death and Fire. Flaming weapons cause an additional 6 armor piercing fire damage. It is not added to weapon's own damage roll. Death weapon works like Flaming, except not fire damage, armor negating and MR negates.

Protection, magic resistance, fire resistance all interact differently with the damage bonus from the bless. Imagine casting Weapons of Sharpness on units with +strength or units with an extra 6 damage armor piercing attack. Of course, the actual damage increase it biggest with fire almost always, as it also increases attack skill, but you can take some Fire for +attack, not always go to 9.

Blood is not that great a path IF you are just thinking about the bless, but for some nations taking high Blood on your pretender is still a good idea because Blood magic in general is so powerful. Blood 9 is weak though, as you don't need it that high for spells.