Sorry if the following happens to repeat feedback you’ve already gotten – I didn’t read through all the notes posted to this thread.

As a rule of thumb, Loglines are best constructed using the least amount of absolutely clear detail. Most working decision makers will have multiple loglines thrown at them every week. If they can’t immediately understand your story, they’ll shut down and won’t waste time/energy on absorbing any more information.

Going off your Revision 2, the logline raises more questions than it answers. For example:
– “…blessed champions…” is unclear; what are they the champions of? In what way are they blessed? Blessed by whom?
– If the MC is a vampire and he’s fighting the vampire counts, how is he uniting his kin if he’s also fighting them?
– Who precisely is he trying to usurp? All the counts? Just a few leaders? Usually, usurping is done to gain control over a single seat of power, whereas here it’s implied that one character will try to take over several. This sounds like less of an attempt to usurp and more of an attempt to overthrow the ruling class by one person to gain power – in other words, a dictatorship. Think about pretty much any dictatorship throughout history – they all thought they were doing the best thing for the people, but how did that work out…?

Producers may or may not take issue with the above, but the fact is that these are legitimate questions, which require clarification. If you end up explaining such complex details (in a pitch) to producers, you can bet on them switching off and likely passing on the concept.