Nereid Card

Normal cards target 2× their original scalable bonuses, ★★ 4×, and ★★★ 8×. Each rank doubles the previous rank. Existing penalties and binary effects stay unchanged, and equipment stacking limits still apply.

★★ can be found from Hard upwards or made through Card Master Fusion. ★★★ never drops; Fusion is its source. Hunting far below your own level does not turn up upgraded cards.