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.
5 Star Servants Tier List: Best Servants [5★]
Best Servants [★4]: 4 Star Tier List
1-3 Star Servants Tier List
Valentine event: Chocolate Lady's Commotion [US 2018]
Nero Claudius (Bride)
FGO Reroll Tier List
Jack the Ripper
Talk on the Heated Sands
Street Choco Maid
Kitchen ☆ Patissiere
Holy Night Supper