This is a self-explanatory achievement. The gamemode highlights the players that hold the flag after they are taken. The game also notifies at the center top screen when your flag as well as the opponents have been dropped, taken or recovered. Simply locate the enemy and kill them popping the achievement. It may be confusing in the chaos sometimes but if you use characters that can kill easy or have high damaging ults like Junkat, you can get it pretty easily.
Some notes for this achievement:
- You also have to do the killing blow, an assist won't make it count.
- You can do this in either the base CTF mode or the competitive one
- You can only get it during the Chinese New Year Event, which usually happens late January to mid-February.
- This is also a good time to get this achievement by standing over the dropped flag if you haven't already: