Mirage is a lesser-known character in ULTRAKILL. She only appears in the secret level for the Lust layer, 2-S ALL-IMPERFECT LOVE SONG.
When first meeting her, she comes off as rude and insults the player. As you further conversate with her, the reason for her attitude sheds light as she reveals her struggles with existential dread. With help from the player, you show her that while nothing in life matters, thats the point. Nothing in life matters in which you are free to do whatever with you life, and that therefore time cannot just be "wasted". It's not a easy task, but those thoughts can improve.
After a long discussion, the player manages to soothe Mirage's worries and dread, leaving her optimistic for the first time in a while.
At first, I didn't really understood why I liked Mirage so much. The first time I saw her it was when my friend came over and played ULTRAKILL on my computer. They showed me 2-S and at first it didn't hit, but to be fair, we had to pause halfway through for something so it took the immersion out. But either way, I understood the level's meaning of course, but it never hit close to home until a while later.
For a long time, since I was around 7, I have been suffering with constant existential dread. It was at it's worst at 7 but it lessened as I grew up, until recently. At around 17 to 18, it had gotten bad. I would frequently have panic attacks and spirals over the fear of death, and why anything I do matters if I'm just going to die and be forgotten. I had only recently found out that this was due to my OCD, a subtype of it called existential OCD.
As my existential dread got worse, I was also starting to get really into ULTRAKILL. To be honest, this game has made me face the topics of death in general, but Mirage specifically made me confront my existential dread. It makes me feel comforted, to see a character that understands what I'm going through. I hope to one day have that weight off my chest like she did after 2-S.