Something very close to you has been killed/hurt, maybe your girlfriend or your child.
I shall attempt to explain the direness of wrath.
If anger had a scale from 1 to 10, wrath would score 30.
When one goes into "wrath mode" one loses are logical or rational thinking and wants only annihilate whatever the cause of the wrath in the most painful and excruciating way possible.
Some trained minds get into an artificial wrath mode called the Berserkergang. these two states are very indentical except that wrath is generally not purposly sought after but happens on it's own .
When the entity responsible for the wrath get's in range of the "wrathee" he will be absolutely terrified.
To be at wrath is a state of absolutism, all or nothing thinking.
The wrathee is completly devoid of their former selfs and will likely keep destroying and killing until either "it" is dead, or everything around it. (somewhat equivilent to Primeape)
The soldier fought with honor on the battlefield, but their opponents did not.
-Enemy soldier stabbed your friend in the back without honor-
- you get into wrath mode and obiterate anything around, regardless of the consequences.-