Some story events are triggered by not having certain cards. For example, if you unlock before the scripted event, the game might freeze. Recommendation: Beat the story normally, then apply the unlocker for the "New Game+" experience.
Before "unlockers," players had to face rigorous in-game challenges:
The actual functionality of such tools can vary widely. Some may deliver on their promises but at a risk to the user's account or device. Others may be scams or ineffective.