Shift to nightmare on killing rare/unique enemy

As per title, this is super broken and doesn't work majority of the time. Out 30 rare monsters and additional 10 unique ones, I was able to shit only 10 times and 5 times of that I got only 2/3, 1/2 of the blood bar at the start.

The way this works (or at least the way that people think this works, and I tend to agree with them) is confusing.

* While you're in the regular part of the zone killing normal monsters, the blood meter is still filling up with each kill as it normally would, even though the meter isn't actually on the screen.

* When you kill a rare or unique enemy, it's as if you pressed the "switch to Nightmare" button.
* That means that if the blood meter is less than halfway full when you kill a rare or unique enemy, then nothing happens.
* And if the blood meter is over halfway full when you kill a rare or unique enemy, then you switch into Nightmare, and now the blood meter appears on screen, filled with whatever amount of blood you actually collected. So the meter might be full or halfway full or anywhere in between.

Maybe I am unlucky, but 8 out of 10 times I killed a rare in Nightmare they didn't drop anything because it shifted me out. Glad I cooked the map to Tier 10, will avoid this map mod in the future!