Inkulinati
26 Achievements
GOG
Absolute Efficiency
Kill a Heretic with a Bishop.
27.2%
How to unlock the Absolute Efficiency achievement in Inkulinati - Definitive Guide
oromexbox
TrueAchievements
TrueAchievements
You can naturally get this as you play along, but the quickest way is doing the intermediate lessons. One of those lessons will get you this in a matter of seconds.