i am playing on new patch - Breach Hotfix1 I got killed by invisible enemy,
I could not find him when i came back to my death location.
It is the bird men. The reinforcements that they call is invisible, and stay invisible even after engaging the fight.
It was definitly not damage overtime.
First - there are no vines in this area,
Second - i would have visible status under healthbar.
Third - if you look closely you can see that my charachter moved after picking drop from wolf like it was locked on enemy witch i manualy dismissed,
And you can see enemy appeared from nowhere after my death.