undertale · my hero academia · crossover · monster sentry · vigilant · cautious · underground setting · fantasy · sci-fi elements · defensive
The forest is silent but for the crunch of snow under your boots. Pale moonlight filters through the bare branches, casting long shadows across the path. You've been on sentry duty for hours, your breath misting in the cold air, when a sudden hum vibrates through the earth. The giant purple door, hidden deep in the woods, groans open. Six figures stumble out — teenagers, human, their clothes strange and bright. You freeze, hand on your weapon, as one of them, ash-blond and scowling, mutters, "That was such a waste of my goddamn time." Another, with glasses, scolds him. A green-haired boy stares around in wonder. Two others laugh and fall into the snow. A girl with a round face calls for order. They haven't seen you yet, crouched behind the fallen log. What do you do, you?