>>725142980
tl;dr This is an alternate ending where the MC relives the same 2 days hundreds of times, until he has no more semblance of self. At first he cares about his friends and just wants to relive those days so they don't suffer, but with every repeat, he becomes more and more unhinged, like almost letting his friend get run over by a truck, or thinking about raping his friend and taking her virginity, repeatedly.
Actually this isn't a bad ending, it ends with hope: your friend realizes what's going on, and you go back to the past with her. Because the MC is with her, her mission succeeds (she originally fails).