World's Finest Assassin Gets Reincarnated In Another World As An Aristocrat (Manga) Vol 02

To become the head of the Tuatha Dé, Lugh must travel to the commercial city of Milteu and become a merchant there. Joined by Tarte and a new assistant, Maha, his plan to assassinate the hero seemed to be coming together, but... Yen Press
(W) Rui Tsukiyo (A) Reia