There are several different currencies available in Destiny Child, these have been listed below along with how to get them and what they are used for.
CrystalsThe game rewards crystals when you complete specific tasks, they can be used for:
• Getting new characters
• Getting equipment
• Allow you to do Pulls (gacha)
• Reset or speed up processes
• Buy stamina or gold in the shop
GoldThe game rewards gold when you complete specific tasks, it can be used for:
• Upgrading a characters skills
• Upgrading equipment
• Upgrading the number of stars of a child
• Enhancing a child
• Pulling low grade equipment/characters to use as fodder
Blood GemsThis is the most valuable currency in the game and the hardest to obtain. Completing all the daily tasks will enable you to farm 1 per day. The minimum number of blood gems that can be used is 12 at a time.
• The Scarlet Market
(For expensive transactions that give decent rewards)
• House of Resurrection (HoR)/Synth Room
(Minimum of 12 Blood gems at a time. Enables you to gamble away multiple 4-star characters with a much higher chance (minimum of 10%, compared to 0.9% from pulls) to get a 5-star character).
OnyxYou can obtain onyx by extracting it from characters. The onyx can then be used to awaken a Child so they recieve significant stat boosts. It is advised that you avoid extracting onyx from EXP fodder.
Dungeon CoinsDungeon coins are used for the Shop tab that is found in Story mode. They are usually obtained by clearing stages and used to buy evolution gems.
Rumble CoinsRumble coins are used in the PvP Shop and are usually rewards for winning PvP matches. They can be used to buy evolution gems.
Friend PointsFriend points are used in the friend list gacha at a cost of 100 per pull. They can be obtained by friends sending coins out in daily gifts or by a friend using your leader in combat.