The World’s Finest Assassin Gets Reincarnated in Another World as an Aristocrat — S1 E11 - Choice of Betrayal

Lugh got a assasination request for Dia. And the principal is Count Viecone, who is Dia’s father and Cian’s old friend. Cian expects Lugh can finish the assasination. But if he refuses it, Cian will do it with his own hands.