Chaos in the multiverse

The Tardis materializes at the Gateway and the team exit the Tardis. 

X-PO:"No, no, no, no!"

Snow:"What's wrong?"

X-PO:"Gwenpool now knows about us. She is creating more mayhem than before. If this keeps up then the whole multiverse will fold in within itself."

Doctor:"X-PO, you need to calm down before you overheat your circuits."

X-PO:"Yeah, yeah. You're right. But that won't help the problem in hand!"

Then the gateway turns on and a person comes out of it.

Ryan:"No way."

Yasmin:"It can't be."

Everyone stare at a kid with white skin, grey hair, black empty eyes, and a dark grey sweater with light grey stripes. 

Bigby:"Who are you?"

Core!Frisk:"My name is Frisk. I need your help with the timelines."

Doctor:" 'Timelines'?"

Core!Frisk:"In other words, help me fix the worlds that shouldn't have been."

Tiffany:"We definitely need to help them, Bruce."

Core!Frisk:"Bruce... Wayne? Yes, you will be more helpful than the rest."

Batman:"Wait, just hold on. How can we really trust you?"

Core!Frisk:"You can't trust someone that easily, I get it. That is what most of you think as well.  But your determination of helping a child is too strong."

Batman:"What? How do you..."

Core!Frisk:"I can see it. Every timeline of you, the good ones I mean. I see you being nice, helpful, and friendly to every child. You can't allow any kid go on the same path as you once did. Trust me or not, they are timelines where different versions of me are falling on the path that shouldn't have been."

Eugene:"They're right. In their game, players can choose Frisk to be pacifist or create genocide. You have to help them, if their genocide paths goes out of what it should be then..."

Tiffany:"It's the end of human life."

Batman:"Alright, how can I help?"

Core!Frisk:"Reach for the Frisk inside of them. Don't worry, your determination will save you."

Core!Frisk enter the Gateway and Batman follow them, then Batman lands on top of a hill. 

Batman:"Frisk?"

Batman looks around and see a city below with a sunset above.

Chara:"Well, aren't you a new one."

Batman turns around and see a kid that looks like Core!Frisk but they have normal skin, red eyes, brown hair, a green sweater with a yellow stripe, and a knife.

Batman:"Frisk?"

Chara:"Oh, you know them. Sorry, but they're gone. But don't worry about that, human. You'll join them quick."

Chara rushes toward Batman and they swing the knife but Batman dodge it and they kept swinging while Batman keeps doing them. Then Chara just throw the knife at Batman's mouth and Batman catch it.

Batman:"You-"

Batman lower the knife as Chara throws another knife and it hit his mouth. Batman falls to his knees while blood drips down on the floor. Chara walks toward Batman and rips the knife out and laugh.