Complex sentence: There are multiple ways to collect characters: some are given to players immediately, whereas others are gained via game play or as in-game rewards in the form of shards that are earned by players to unlock and or promote their characters.
Split into simpler sentences: There are multiple ways to collect characters: some are given to players immediately, whereas others are gained via game play or as in-game rewards. The in-game rewards are shards that are earned by players to either unlock, or promote their characters.