How Do Unexpected Guests Affect Undertale Gameplay?

I transmigrated into a dating-sim otome game where I was supposed to romance a soft, fragile male lead. I had finally pushed him onto the bed and was just about to make my move when the long-missing system finally popped back online. [Host, I sent you to the wrong game. This is a horror game.] [The man you’re bullying right now is the horror game final boss.] I lifted my head and met a pair of blood-red eyes staring straight at me. My smile froze. “Um… you look a little tired. Maybe we should… continue this another day?” He smiled back, calm and terrifying. “I’m not tired. Go on.”

After entering a horror game, I, Anastasia Moreau, begin dating the big boss. At our first meeting, I wrap my arms around his sleek, serpentine body and squeeze him into a corner of the coffin. "Move over, move over." In the next instant, a strikingly handsome young man with white hair and golden eyes appears beneath me. The tips of his ears flush red as he glares at me. "You… You're lying on my hair!" he grits out.

I was always sick as a kid. My parents were desperate. They’d try anything. So they got me a bunch of "guardian angels." Next thing I know, I'm set up and tossed into a horror game. Turns out, Medusa is my godmother. The ghost girl? My childhood playmate. And the final boss, a vampire? He's my fiancé. The first time we met, I was in a blind panic. I tripped and fell right onto his chiseled chest. "Oh—I'm so sorry! I wasn't looking—" I gasped, looking up at him. The words tumbled out in a rush. "And you're really handsome—but I didn't mean to fall on you! I have a heart condition!" The boss let out a laugh. He wiped the blood from his hands and swept me up into his arms. "Don't you worry," he purred, his voice dangerously smooth. "As your fiancé, I promise... I'll fix you right up."

Anomalies were descending on the world when I got thrown into a horror dungeon. The problem? I was a hopeless romantic. An even bigger problem? The dungeon’s final boss turned out to be more of a lovesick idiot than I was. The moment he saw me, he practically begged to be my personal simp.. Me: Wait… we’re doing that already? The barrage of comments exploded: “Look at him. The mighty final boss is willing to be the third wheel.” “Sorry, sweetie, but our girl already has two anomalies in line. Even if he’s the boss, he still has to take a number.”

After being chosen by a horror game, I took over a food stall in a small town. A ghoul tried to eat me, his huge, bloody mouth a gaping maw, but I quickly shoved a focaccia sandwich into it. He chewed and then said, “Oh, forget it. With food to eat, I’ll kill her tomorrow.” The next day, I made delicious pierogies, then skewers and stews. All the ghouls who stopped by gave up on trying to kill me, focusing on eating instead. The audience watching me was shocked that I could survive all the way to the end with just my cooking.

On Christmas Eve, my uncle, Garrett Wayne, takes a sip from the fancy whiskey I bought. Then, he points at me while grinning. "Well well well… I've been watching you since you were a kid, Flint. You were a bed-wetter when you were a little boy, and now that you're all grown up, you stay cooped in your parents' shop while running that social media account of yours. You don't have any skills at all. "My Ronnie, on the other hand, has an amazing job that will continue paying him and keeping him around no matter how hard times get. Small businesses like your family's will definitely crumble as soon as the tiniest change happens in the global economy!" All of my relatives roar in laughter at Garrett's quip. My cousin, Ronnie Wayne, pretends to be playing on his phone, though his grin has already become ear-splitting. Mom and Dad can only laugh along as well even though deep down they are very uneasy and anxious. I just gaze at Garrett coldly. In six hours, the blizzard apocalypse will descend onto this world. At the same time, a zombie outbreak will occur across the globe. In my previous life, Garrett, who had looked down on my family and me, didn't hesitate to push us into the upcoming zombie horde just to take over my parents' grocery store. In this lifetime, I swear that I will never let him off the hook! I'm about to pick up a plate of food and smash it onto Garrett's head when I hear a mechanical voice chiming in my head. "Ding! You have been bound with the Rage System! You may talk back and retort to others to your liking in exchange for supplies. The more arrogant you sound, the better supplies you'll receive!" As I look at Garrett's insufferable face, I let out a chuckle. "Oh yeah, I'm not skilled at all. But I suddenly remember this funny little thing. Uncle Garrett, you claimed that you had gone on a business trip to Brimstone eight years ago. But the truth is, you got arrested by the vice squad, right? "Does Aunt Cassia know about this?"