Diablo III has a set of three Achievements that can be earned by killing a certain number of Champion monsters. The three Achievements in this set are called “The Takedown”, “Not So Tough Now”, and “Champion’s Collection”.
Champion monsters are blue (and typically come in packs of three or more). If you play Diablo III long enough, you will eventually earn all three of the Achievements in this set. Just keep going after the champion packs!
The Takedown is the first Achievement in the set. I completed it on May 27, 2012.
The Takedown: Kill 10 champions of the following types.
Not So Tough Now: Kill 50 champions of the following types.
I completed the second Achievement in this set on February, 11, 2013.
I completed the Champion’s Collection Achievement on November 14, 2016.
Players who complete the Champion’s Collection Achievement unlock two Achievement Rewards: a Banner Sigil and a Banner Pattern.