Grants 100 XP upon completion.
This challenge is repeatable.
- PC The challenge gets stuck upon reaching the 4096/4096 goal and after that every single energy weapon headshot for the rest of the game triggers the XP award and displays the achievement message without actually marking the challenge as complete.
- Xbox 360 Similarly to the PC bug, this challenge may never complete. Instead, upon reaching 4096/4096 it will simply reset to a lower value. Unlike the PC bug, however, it does not seem to be possible to get infinite experience (or any at all) from this challenge.