Holy Duration: Repentance

I just realized that holy powers don't have any means to curse a sinner "until he repents his sin." As the Infernal has a Forsaken duration (used in a different way), this seems to be something of a severe oversight, so I came up with a Repentance duration that's functionally identical to Forsaken.

I wonder, however, whether it should be a +3 or +4 duration. Unlike Forsaken, the duration is pretty much limited to negative effects, but I'm not sure whether that would be enough reason to reduce its magnitude.