Amrita and Soul Cores
Farm Ippon-Datara Soul Cores near the Water Mill Shrine
Target Ippon-Datara for its specific Soul Core using the two-enemy cave route near the Water Mill Shrine in Maisaka.
The cave near the Water Mill Shrine in Maisaka, where the Nioh 3 Soul Cores guide lists two Ippon-Datara.
Repeat the two-Ippon cave pass after praying at Water Mill Shrine, which respawns defeated enemies; continue only while you still need this specific core.
Stop when you have the Ippon-Datara core you need or when the repeated cave pass is no longer worth the time; pursue another upgrade target afterward.
Open a guide to find other locations and see what the item is used for.
Target Ippon-Datara for its specific Soul Core using the two-enemy cave route near the Water Mill Shrine in Maisaka.