Bumblebee

Where are you using Backslide? It might be disabled for some specific maps such as BG/WoE (I believe).

Heyo, The 'Allied Solider' is the Mobster! The guide probably says "kill the Mobsters" because the sprite being used for the soldiers is the same as the Mobster mob. Just keep killing them until the map announces you're finished and then go back to the NPC. I don't think the quest actually requires 50 kills, just for a certain amount of time to pass(?). Good luck!