Total War: THREE KINGDOMS

This achievement is to defeat Dong Zhuo's army in battle. This can be a bit annoying normally because unlike most of the factions, Dong Zhuo doesn't start with himself deployed on the map. He has a fairly expensive starting retinue as well, so the AI tends to pass over him when deploying new generals. I think the only way to force him out naturally is to keep killing off or converting his generals (good luck with Lu Bu) until he doesn't have any left. The other option is to annex him, then liberate him as an administrator. This essentially resets him as a faction and the only character he should have available to start is himself. He starts with some gold, but probably not enough to make the AI think it's worth recruiting anybody else immediately. For a more in-depth process, see the Diaochan's Revenge guide.