Bad Boy Marco wanders the streets of Echo Creek, finding it devoid of life.

The air is cold, silent, still. "Star?" He calls out.

...

No response, expect for one sound. The sound of a blade against its scabbard. Marco turns around, to see a cloaked figure with a broken wand in one hand, and a long sword in the other. The cloak hides the figure's face, as he speaks, "27."

"What?" B.B. Marco asks.

"27," he repeats, "27 threats."

"Theats?" B.B. Marco asks, "what do you mean? Who are you?"

"I am a man with a name to match my worth. You may call me Zero, for I am worthless."

"Edge alert!" B.B. Marco shouts with snark.

"I have come, to kill you."

"What?" B.B. Marco steps back, putting up his fists.

"27. You are the fourth I will slay."

"Threat to what?"

"Her."

"Who?"

"The one who died for me. Now, you die for her."

The man lunges with impossible speed, and stabs B.B. Marco, killing him. He takes one his earings, and wears it like a trophy. He takes out a list, with ten Hekapoos, ten Toffees, and nine Marcos on it. He marks our "Bad Boy Marco." Also marked out, are the faded names of a Hekapoo and a Toffee, but it's unclear which they are.

"May as well get the others," he thinks aloud, taking a pair of scissors and heading to the dimension of the Hekapoo from the AU. He doesn't speak to her, and merely stabs her in the back. He takes her scissors, and puts them in his pocket. He proceeds to that Marco's Mewni, where the timeline's Toffee is facing Moon.

He leaps into the fray, killing Toffee with a sudden strike.

"Thanks," Moon offers her gratitude, "what's your name?"

"Zero," Zero explains, "I have no further business here."

He marks off the names of a Hekapoo and a Toffee. It's clear Hekapoo was displaced when the timelines broke off, which is why she was even there to kill.

Zero leaves, and continues searching for his next target. He takes out a photo. It appears to be taken recently, and shows a tombstone. He covers the name with his thumb and starts crying.

"I'm sorry," he puts the photo in his pocket, "that I was so worthless. I will not fail you again."

He looks at his list.

"24," he reminds himself, "24 threats remain..."