Some targets on the battlefield may drop special items or tokens. They grant useful bonuses when cubed with the Class Charm you picked up in Kurast 3000 BA.
You need your Class Charm
This challenge requires you to have your Class Charm. This is a charm that drops in the Kurast 3000 BA uberlevel. If you did the Ennead Challenge, you already have one.
If not, see THIS PAGE for more information about Kurast 3000 BA.
In Terror and Destruction difficulty, you can find veteran monsters near the end of each Act. There are 5 types of veteran monsters, one for each Act.
Kill them and receive an 'Evil Eye' token.
This upgrade recipe adds the following bonuses:
+1 to [Your class] Skill Levels
+20% to Experience Gained