| Achievement Category | Zero Key |
| Description | Upgrade your squad 30 times during explorations in “The Mystery of Arpeggio Fault.” |
Hitting the Sweet Spot
| Achievement Category | Zero Key |
| Description | Upgrade your squad 30 times during explorations in “The Mystery of Arpeggio Fault.” |
idk about Promeia synergy, but i plan to use her with Nangong Yu (or Vivian sometimes) and Yuzuha.