Instructions
Join any multiplayer match. Tactical Insertions are more commonly used in Free for All and Capture the Flag matches, but you can play any type of match you want.
Explore the map until you find boosters. It is fairly common for players to drop Tactical Insertions near boosters so they can grab them immediately after respawning. If you find a booster, but no Tactical Insertion, keep exploring until you find one.
Walk up to the Tactical Insertion. A button prompt will appear on your screen. Press the appropriate button on your controller to deactivate the Tactical Insertion. Repeat this 25 times to complete the Darkbringer challenge and get the corresponding emblem.