Gruel Irradiant is so bad!

Why Gruel Irradiant is so hard for get more than 2 success in row ? I've already lost 14 humans 91~98% and the maximum successes on the same human were 2.

No exist no way for this (%) make better ? this just eating my time and make me angry.

EDIT: 20h after this post, i catch random Rogues and brutes with 78%~96% Blood, and, well... one rogue 79% became 100%(i laugh, serious)... Thanks for the comments bros, my war with gruel came to an end, for now!

https://preview.redd.it/e7g1i9wvvmce1.png?width=475&format=png&auto=webp&s=e52730de2ee0263694d7baec20d46f9814b860f8