Sekai Saikou no Ansatsusha, Isekai Kizoku ni Tensei suru

Synopsis

Lugh and Tarte spend a full month on a deserted island as part of their assassin training and upon returning to the mainland, Maha gives them information about a divine treasure, a tool of immeasurable power, that Lugh has been trying to purchase for some time. This divine treasure, a magical spear called Gae Bolg, is in possession of Setanta MacNess, a renowned warrior suspected to become the legendary Hero. Lugh also discovers that the Viekone region is involved in a war and rushes to Dia's house, offering her a way to escape should the war reach her doorstep. Dia refuses to abandon her home, stating her obligations to her family and her people. Even so, Lugh and Dia decide to enjoy themselves on a date. As Lugh returns home, he still thinks he can help Dia escape from the war; but Dia has already taken steps to defend herself by fortifying her hometown. Sometime later, a wounded soldier asks the Tuatha Dé family to assassinate Dia.

(Source: Wikipedia)