I hate to be the one to tell you this, but this whole ritual sacrifice thing going on here, while very nice, just isn’t going to work out the way you’ve planned it. Allow me a moment to explain.
The great old ones, they’re kinda like food critics. If you can manage something pleasing to their palate, they’ll provide you with plenty in return. But, they’re really picky and easily bored.
You try to serve them the same old sacrifice they’ve had before, odds are they won’t hate it, but they won’t like it either. You’ll get a middling review, they’ll spare your life, blah blah blah.
That’s why most of these rituals don’t work. They might have worked, once, back in the day, when they were new, and that’s how the recipe got written down in the first place, but following the same recipe isn’t going to cut it.
Of course random improvisation isn’t always such a great idea either. I’m sure you’ve heard the rumours of rituals gone horribly wrong, and mess that results. That’s them being displeased. There usually aren’t many details, but the pattern is there, if you look for it.
There are occasionally those that get it right and gain whatever it was that they wanted badly enough to perform the damn ritual in the first place, but those are few and far between.
Just between you and I, I think it’s more a case of a lucky accident than anything else. But you’re the high priest, you’ve got the fancy altar and the pointy knife, I’m sure you know best.