Rate and Critique my homebrew hook

My homebrew magic system is somewhat inspired by Dark Souls. Souls have a value based on alignment and good or bad deeds done. A person isn’t just one soul but could be many souls. The Kings mages have determined that killing evil wizards, warriors, demons etc has kept the cycle of evil going. The alliance kills one necromancer and another pops up a short time later. The maintenance that mages do preventing the rise of evil before it starts is a financial burden on the realm.

The King is looking for adventures and party’s to capture the souls, dead or alive, of evil alignment creatures. The party will seek to clean up a part of realm. Then banish who they’ve caught. There’s obviously more moving parts and NPCs with different motivations. All the players are new and their backstories have will influence sessions. But that is the overall hook that will grow and evolve throughout play.