Forgiving Cruor gains when you are wielding a poisonous bite against an enemy.

Seems odd, given the skill.

civilized <539hp 439m 267mv 4502tnl (65.89%)>
A war-weary storm giant's punch misses Nelethe.
A war-weary storm giant's punch maims Nelethe!
Nelethe delivers a blow of deadly force!
Nelethe's claw MUTILATES a war-weary storm giant!
Nelethe's slice EVISCERATES a war-weary storm giant!
You have become better at forgiving cruor!
Your poisonous bite misses a war-weary storm giant.
Your slash maims a war-weary storm giant!
A war-weary storm giant parries your poisonous bite.
A war-weary storm giant is writhing in agony.

I did have envenomed weapons at the time.

n/t