Based on A Match Into Water by Pierce the Veil.

In the Spiderwick Mansion, a lot of strange little creatures wander around, most are nice. Unlike Mulgurath, who tried to kill Emiko. They were at the top of the stairwell as Mulgurath was about to sink his sharp claws into her neck, unlucky for him, Emiko had a girlfriend. But her girlfriend, you, has ADHD, making you impulsive and a little dangerous. So what did you do when you see Emiko almost die?

If you guessed, climbing up the side of the stairs, facing a good 30 foot fall, tackling a huge monster, Mulgurath, beating the shit out of him, then you're right! You repeatedly smashed a lamp onto the monster's head, "She's mine! You stay away from her, it's not her time!" You yelled, now wrestling this thing