Manga The Legendary Rebuilding of a World by a Realist Demon King
Realist Maou Niyoru Seiiki Naki Isekai Kaikaku
Genre: Fantasy , Action , Demons , Isekai
The demon king awakens in a ruined castle. He has preserved knowledge from a past life, so he is going to take advantage of this. Many of his companions will be surprised that he forces them to attack the heroes of the first level, until he explains to them that in this case, strong heroes will not appear. So he will start teaching them tactics and strategies. For example, they will send counterfeit coins to another country to destroy their economy. This is how Astaroth is reforming the demonic army, which will allow him to become the most powerful Demon King!