Zhang Qifeng, after a brief consideration, decided to start a new save.
Of course, he also carefully preserved the previous save file that only contained Yarvette.
Although the game had both auto-save and manual save functions, considering the capricious nature of the game, any save file could be potentially deleted or corrupted by an unknown force at any time, so Zhang Qifeng smartly created a new folder on the hard drive outside of the game's root directory as a backup for the saves.
That way, whenever he wanted to play any save, he could directly copy it from there.
Actually, this method is quite common in regular games.
For example, most high-difficulty action games nowadays do not offer a save function to players anymore. "Ascension" is one such game, where players can resurrect infinitely after death, but the consumables used up can't be obtained again.
Bosses that have been defeated can't be fought again until a second playthrough.