Gods Will Fall

Enemies who attack with a red glint are using deadly attacks. It's easy to not think about dying to one of these attacks on your first run but it's hard to remember which enemies have them.

The fastest way to get this is to enter Methir-Shirraidh's domain at the start of a run and look for one of the enemies wielding an axe/club. The attacks from this enemy are always deadly so just die to them and you've got your achievement.