There is definitively a bug in that you *always* get a screen saying "Victory", even if you lose or forfeit. That false victory also always rewards you 100 gold. But you don't get the allies collected. Winning on a second try I didn't get the allies either, but I did get to advance.
About strategy: Somewhat counter-intuitively the key to strategy in this scenario is to *not* close locations. That way Black Magga ends up going to open locations with no cards left; also with 4 characters there are 3 locations which need you to banish a card to close, and as you don't need closed locations to win, you can save those cards. If you have the Village House location, try to do that one early, because the "recharge to gain ally" ability is a winner.
There is not always the victory. I lost it yesterday, relieved clear message that Magga ate more allies than I saved and have' recieve do any money.