For a Killing Wave, I pay life for some of my creatures so that my life total falls below 5. I sacrifice the rest of my creatures. Is “Fateful hour” of my Gavony Ironwright taken into account for the sacrificed creatures so that they trigger the ability of my Kheru Bloodsucker?

My guess: No. Even though Killing Wave is written as “For each creature…”, it isn't done one by one in a certain order. I rather have to decide what to do with each of my creatures, and then that is done all at same time: pay X life and sacrifice Y creatures. When I want to know what toughness the sacrificed creatures had when they were still in play, I have to go back to the moment before they were sacrificed, and that's the same moment when I hadn't paid life yet. So they miss the boost of “Fateful hour”.

Mario Hassler