What is the path of blood for?

[Executor]

National troops (most of them) became obsolete at a certain point in the game, and by that point you'll be switching to blood summoned troops, be it national summons like Mictlans or Lanka, or sinergetic summons like storm demons for Vanhaim, devils for Abysia, etc.
In any case, you'd ideally want to stop recruiting regular troops and indies altogether (except for mages) and completely switch to a blood economy, even blood forts are relatively cheap, 120 slaves I think.
Strong blood powers should play it so at least.