The Titan Shield augmentation is required for this achievement. Once you see an enemy grenade in your vicinity, activate the Titan Shield and move close to it. When it explodes you should get the achievement.
A good place to be awarded it is in Otar Botkoveli's underground casino. Once the Dvali are hostile, run upstairs to Otar's office. Rather than entering the room after you, the enemies should instead throw a grenade into the room. Run towards it and activate Titan Shield, getting you the achievement.
Additionally can be obtained by walking into a "Frag Laser" mine while the Titan Shield is active.
- The achievement's name is a reference to the movie Casshern, based on the series of the same name. The tagline for the movie was "reincarnated with an invincible body, to fight an iron devil."