Viper
Viper “Yea….I mean, lots’a people from the church turn ta it after goin’ through stuff, right? Sure ‘dat was what happened wit’ ya.
Sister chuckles, happy to tell the story.

“….Truthfully, I only ended up in the church by a matter of… happenstance. At first, I was only there because it gave me a roof over my head when I had none. And I had ended up staying for the… community, more than anything else.” Community nun code for 🏳️🌈 btw.
“…But in essence, yes. You could say that.”
Viper “I…was a criminal too. I get it. Definitely on the database of wanted people. I…look, I…used ta sell backdoors for people ta hack inta big systems. Like…hospitals, banks, even government agencies… I…didn’t care. Who it hurt. Yeah, I didn’t do th’ takin’ down part m’self, but… usin’ skills my dad taught me for such…selfish motives?”
Sister listens, intermittently taking sips of her tea. She won’t pass judgment, that’s not the job of the women of the cloth, after all. It’s to offer support, just as she—they had for her.

“….Perhaps it’s a bit shallow to say it now, but… everyone makes mistakes. My crime… it started small, but… grew larger, more dangerous, as I grew older. Then one day, someone important to me hurt me, and I… lost it. It grew out of control, and…” With what Viper knows about Atsuko, it’s not hard to guess what the ‘crime’ might have been, even though Sister is remaining tight-lipped about it. “…I didn’t care who I hurt. It was always about me, and my wants. I… received a wake-up call, not long after that. And everything that came after is… a painful story. And this is about you, anyhow.”
Topic changed! After she’s the one who brought it up. Smh.
Viper "They talk ta my roommate nearly every day ’bout me. So…they know I’m like, alive…but… I do th’ same for her parents. We both got issues, so…we look out for each other.”

“…That’s a relief, that you’re not completely alone outside of this train. The journey you and your fellow Passengers have ahead of you… both the one through the train, and within yourselves… You can’t achieve it alone. And that will be the same even when you leave this train. Remember… that you aren’t alone. And should you successfully reconnect with your parents… You will have their support, as well.” How idealistic.
Viper “…'Nuff ‘bout me, though, Sister. I gotta know…ya got some weird business goin’ on. Ya ain’t a denizen, are ya? Ya a passenger, jus’ like us.”
Viper has used the Uno Reverse on her.
Sister takes a sip, not hesitating in her answer.
“I am a passenger, yes. I’ve… made myself an honorary denizen, I like to think. I don’t have any plans to leave this car, let alone this train, anytime soon.”
Viper “…Sure ya had people comparin’ ya to our Atsuko who died, but… I’m kinda wonderin’ if there’s more of a link than maybe even ya wanna admit. Ya a twin sister or somethin’? …Ya can tell me. I got no reason ta spread ya secrets ’round.”
Sister chokes a bit on her tea at Viper’s bluntness. She doesn’t know how to respond to this, how to… justify something she doesn’t even understand herself.

“……I suppose it’s completely possible I have a twin sister I never knew about. My birth mother and father remain a complete mystery to me, even now…” Yet another similarity, check! “But I can’t think of a situation where that would even be… possible.”
She sighs, setting her tea down on the table.
“I don’t know. I really don’t. I’m sorry.”
Whether or not Viper decides to believe her is her own decision. If nothing else, it’s worth nothing that the small wrinkles beneath Sister’s eyes, whether from age or exhaustion, could lead one to the assumption that she’s at least slightly older than Atsuko was.