Night Stalker: Shh! There's Something Weird Here!

Transmigrated to Blue Star, he wanted to play dumb to survive. But this place is off—people keep disappearing in the urban village, yet the news says 'the culprit committed suicide out of guilt.' Until he saw with his own eyes the old man who often basked in the sun at the alley entrance bite off half a patrolman's face. He was scared stiff, and a drop of blood from his wound fell on the old man. He caught fire. Yes, literally, burned to a pile of charcoal. He looked at his hand, then at the ashes on the ground. Oh wow. That's a big deal. From that day on, all the monsters in the city were looking for him. Coincidentally, he was also planning to go find them. — Description from novelcodex.org