Question: bbs how to get immutable balls?
Answer: Select a max level base Accessory from the Accessories screen.
Tap the "Evolve" button.
Select another max level Accessory of the same rarity from the Accessories list.
Tap the "Immutable Balls" button and then tap an Immutable Ball of the correct rarity to add it to the "Items to Fuse" list.
Tap the "Evolve" button.