How to Complete Abundant Evil Myth in Nioh 3

Abundant Evil is one of the first Myths that will pop up right after completing the first Crucible section in Nioh 3 and defeating Jokutsu-Baba. As you make your way to the top of Hamamatsu Castle, you will talk to Honda Tadakatsu, who wants you to check out Maisaka Post that has been seized by the Yokai.