Which creature would be doing this?

[g33k]

Oh no, it just makes it easier. The whole reason the Reds were performing SO MANY sacrifices to charge their bloodline curse was so it could get through all of Eb's powerful defenses to kill him. 

Hmmm.  Has this understanding been confirmed via WOJ?

Because I note that the ritual got the *ENTIRE* Red Court, including the King and a dozen or so LoON's (who are (EACH of them) nearly Vaderung-level badasses), plus other RCV wizards & Powers of various stripes.

Granted that Eb probably has personal defenses among the top-5 of all mortal wizards, PLUS probably some Entire-Council-backed buffs (not to mention whatever unknown stuff he gets from wielding THE Black Staff).  Hard target, no two ways about it!  But remember also that the LoONs are power-mad megalomaniacs who don't trust one another; each LoON has been accumulating personal power for millennia, and has the expectation that the most-likely foes will be the peer-group -- other power-mad megalomaniacs who have been accumulating power for millennia.  Each will be at least as hard a target as Eb, and the King harder in turn than any one of them...

All taken down by the one ritual.
 

[blackstaff67]

I'm gonna guess that the Ritual allowed them to satisfy whatever Catch he may have had, since it's tied directly to his bloodline and him. Pretty good chance it satisfied their Catch as well.

[dragoonbuster]

Hmmm.  Has this understanding been confirmed via WOJ?

I could be remembering Changes wrong but as I remember it that was pretty well spelled out as what the point was.

And while your point about the strength of the LoON and Red King are true--they had no idea where Eb would be and have no idea what his defenses are. If he was sitting in Edinburgh--which he would've been, if he hadn't come out to fight with the Gray Council, since the Duchess Ortega had called a conclave and whatnot--then they've got to get past the layers and layers of Sidhe and White Council wards sticked onto it for so long before they ever get to Eb's personal resources. If you have just one bullet to use, you make  sure it's big enough to do the job.

But we're off topic. Either way--the original point was that blood bypasses thresholds and protections. My point is I wouldn't judge it a complete catch-all, but it is a powerful starting point and will take you a long way there where without it you'd be looking at something that's impossible.

[Quantus]

Changes established that the Real target was McCoy, and DB had already established that it would take Power on the scale of a freshly birthed /god/ to get past the defenses in place on the SC.  I didnt find a repeat of that part in Changes, though the conversation sure seems to take that fact for granted.