Class 1A were at the blacksite to retrieve the crystal

Deku: "Why are we here??"

Uraraka: "No idea."

Bakugo: "It's for this bullshit crystal."

Eri was distracted and fell behind. Suddenly the lights flickered. Followed not far behind by the sounds of scraping metal

Eri: "Oh no! No no no no no!"

You enter the room slowly. You are a brown color. You resemble a humanoid creature made of metallic sludge. Your eyes sockets are lifeless and your mouth is massive. You have no eyes at first. But the moment you see Eri, you show your eyes in your eye sockets and another 14 smaller eyes in you mouth. You make a screeching sound which sounds like scraping metal.(And, just throwing it out there, you can change your form like the T-1000 from Terminator 2 Judgment Day)

Eri was terrified out of her mind

Eri: "AHHHHHHHHHH!!!!!!!!!!"