This is one of the many achievements that can be earned in Infestation Mode. In order to obtain this achievement, you must make your enemies kill themselves while shooting at your shell.

Here’s a short guide on how to achieve this:

1. First you will need this Tier 4 Shell Upgrade, Reflective Shell. This costs 1,500 salvage. To use Shell, hold and press (in campaign) or press (when it is selected in Infestation) whenever your nano charge is full.

2. This will enable a large nanite shield will form around the player, that reflects enemy explosives with the Upgrade Reflective Shell. Weaken a Ravager as much as possible, then cast a Shell and have it shoot at you while you’re behind the shield. If the Ravager is firing an explosive projectile as opposed to the standard laser projectile, it will reflect back at them.

3. This is where you’ll hope and pray that it will kill itself. And if it does, you’ll see the achievement pop out of the right side of the screen.

Here below is a video on with regards to this guide: