The Mystery Patron conceded that you deserve some reward, for 'furthering the cause of Life' (that is fighting Zombies). She revealed that Sivalinga Stones are powerful artifacts of Life Magic, and can be used to literally resurrect 'heroic souls, who haven't become one with the Ether yet'. With the proper rites, she can channel her powers through you to achieve this feat, but the recipient must have high BRA, REA and VPWR, as well as the Valkyrie Condemnation.
This power has other limits as well - Gals whose corpses were vaporized, melted, eaten, squished flat, or exploded into pieces, can't be raised.