Skill Up & Ascension MaterialOminous bones wielding curses.
Fuyuki: Unknown Coordinate X-C is the best AP-saving location to farm Evil Bone. You'll get around 2x Evil Bone by spending 40 AP.
Fuyuki: Unknown Coordinate X-C is the best time-saving location to farm Evil Bone. You'll get around 6x Evil Bone by spending 150 AP.
Here is a list of servants that need Evil Bone to perform Ascension and Skill Up.
Rashoumon event (Ibaraki Douji event)
Murder at the Kogetsukan
Inheritance of Glory
Best Servants [★4]: 4 Star Tier List
5 Star Servants Tier List: Best Servants [5/9 updated!]
Archer Inferno (Tomoe Gozen)
FGO Reroll Tier List [5/11 updated!]
Kato Danzo (Katou Danzou)
Yagyuu Munenori (Saber Empireo, Yagyuu Tajima-no-Kami Munenori)
Best Craft Essence: Craft Essence Tier List
Nine-Headed Bull Demon King
Maiden Leading Chaldea