Life-Winner Cong's Double Dragon Dream - Get all characters

IMPORTANT TIPS: Purchasing but not installing this DLC does not work.
Purchasing and installing this DLC will have the following effects:
1. Instantly and permanently activate all characters, whether or not you reload or restart the game. There's no need to brush love values any more. Why not?
2. After the start of a new game, you can directly select any round (any difficulty level), no longer need to start from the first round.
3. But you can't get love values while DLC is in effect.
4. If you don't want to use this function for the time being, just uninstall this DLC. Re-installing this DLC will activate all characters again. It's quite convenient.