A quote from the rules:
Special abilities on sites are not affected by character or enhancement cards. New Jerusalem (Site Card), Dragon Raid, and Promised Land are mainly used offensively as "access sites" and therefore their special abilities are written to take effect when they enter battle and at no other time. All the single color sites are mainly used defensively as "lost soul sites". The special abilities on single color sites like Nero’s Realm and Leper Colony are written to take effect when they are holding a lost soul. Therefore, if you are using an "access site" defensively or a "lost soul site" offensively the special abilities don’t activate.
From a sample game:
Draw 3: (Servant Angel, Lewd Men, Lost Soul). Lost Soul in Land of Bondage, draw
replacement (Angel of the Lord).
Prep: Lost Soul in Tree of Knowledge site.
Battle: Rescue attempt with Angel of Revelation (8/8 silver hero). Bryon blocks with
Oppressive Women (7/7 gray evil character). The evil character is losing, so Bryon has initiative.
Bryon plays Deluge of Rain (Gray enhancement “Discard all cards in battle, including yours.”).
Kurt has no silver enhancement that can negate that effect, so all cards in battle are discarded.
This is mutual destruction by mutual removal, so no Lost Soul is rescued. The score is still tied
2 to 2.
Discard to 8: Kurt places Servant Angel, Servant Girl, and Guiding Angel in his territory.
Card image courtesy of this Flickr set from Chris Noessel.