Madan no Ou to Seisen no Carnwenhan

Tigur, a young archer who works for Eren, the warrior princess of the Principality of Lightmeritz, and Lim, Eren's second-in-command. For some reason, the two are now isolated in the midst of Asvar, an enemy nation that has suddenly invaded Zystart. There, they are told an unbelievable story by Princess Guinevere of Asvar. Artorius, the founder of Asvar, who is supposed to be 300 years old, has suddenly risen from the dead and has taken control of the country in the blink of an eye. The two decide to cooperate with Guinevere, but they are confronted by a mysterious man who has more power with a bow than Tiggle, and who calls Tiggle "the king of this generation." In a foreign land, Tigur and Lim are confronted by a fearsome enemy.

(Source: Shueisha, translated)