The below chapter provides a complete walkthrough for The Two Kings: Nioh. It provides a solution to the challenges in the side quest of the game, which will allow you to complete it in the best possible way.
In this mission, there are two opponents to defeat. They are very strong, because they are Tachibana Muneshige and Honda Tadakatsu. This would not be too difficult, if it hadn't been for the fact that you fight them both at the same time. The item that will make it much easier is the amulet of idleness. Cast the spell on Honda Tadakatsu, because he is, in himself, very slow, and deal with the other boss. The battle takes place on a large arena and therefore, there is enough room to dodge the attacks.