- Merc Storia Gacha:
During event period, if player move to Rare Cat Capsule/Gacha screen, Merc Storia Gacha can be accessed by using Gacha Switch Button at the top-left screen. There are 10 characters can be unlocked in this gacha.
- Merc Storia Stage:
During event period, if player go to Stories of Legend Mode, 2 chapters of Merc Storia can be played: 「対決！メルクストーリア」 (Confrontation! Merc Storia) and 「地獄のメルクストーリア」 (Merc Storia Inferno). There is an EX/Special Cat Healer only available as a treasure drop.
- Benefits from Merc Storia:
An Ex/Special Cat Merc can be unlocked by installing the app Merc Storia.