For the extermination of barbarians, one of the best civilizations is Arabia. As we all know, Arab civilization is suitable for the development of cavalry, because they have a strong offensive. In this civilization, your army causes 10% extra damage to barbarians and neutral units. This advantage will undoubtedly make it easier for you to win against barbarians or neutral units.
For the extermination of barbarians, another civilization worth trying is Germany. This civilization will increase your action point recovery rate by 10%. This allows you to hunt more barbarians. With this advantage, you can develop your country faster than other players, and the training time of the troops will be reduced, which will allow your advanced troops to complete faster training.
Finally, China is definitely a civilization worth playing. This civilization will increase your action point recovery rate by 5%. However, this is not the main reason why I recommend you to choose China. The main reason is that if you choose China as your civilization, all your troops will increase their defense power by 3%. This means you can attack more savages.