This is a spoiler: She is emotionally invested because actually she has experienced that b...

This is a spoiler:
She is emotionally invested because actually she has experienced that before. She also know this people(in game) . . . . . . I mean she is the Original Villainess

her soul left the game world as she was getting killed and abused over and over again(that's because of that white hair magician who is making the time go in a loop so the world[game world] wouldn't end[cause of Heroine who is actually a witch just wearing the outter shell] )

the only way to stop the loop is when Villainess wins but couldn't so her soul shattered and some came to normal human world . . . . so yah.

How the game can to the normal human world?
White hair magician tracked MCs soul (as only MC/villainess can brake the loop/stop the heroine) and somehow found a way to bring her back so that's how the game came to normal human world by magic ٩(๑❛ᴗ❛๑)۶