I bought an instant-death gem from the gem shop hoping to increase my one-hit kill rate, but after socketing it into my leg equipment, the trigger rate was ridiculously low. Just as I was about to replace it, the effect suddenly triggered when I was fighting the boss in level 101. The boss disappeared instantly, and a "Lucky Duck Blessing" pop-up appeared on the screen. It turns out this gem is specifically designed to counter high-HP elite monsters.