Characters can be unlocked by obtaining a certain number of corresponding shards.
Unlocked characters can be used in teams and Synchros.
The number of shards required to unlock a character depends on its initial rarity:
N: 10 shards
R: 20 shards
SR: 60 shards
Only one copy of each character can be unlocked. Any additional copies are converted to shards.
After a character is unlocked, their shards can be used for increasing its rarity.