<Gwen> the innocent and <Gwen> the pitiless in Yowyn. When used, it grants a feat which increases Karma maximum by 20. The only real benefit from this, aside from being slightly harder to become a criminal, are the tax breaks for having higher karma (5% for every 5 above 0). It also increases all karma penalties by 50%, rounded down - meaning that all acts that were -1 still are.
It does not affect karma minimum or karma gains, and it does not stack with the secret treasure of the wicked - one will erase the feat granted by the other, replacing it.