When Jinx was young, she was sweet and caring. Unfortunately, she accidentally killed her family...
Swain's rework brings many special interactions. Here's an interpretation of his mysterious quote to Jinx.
Here's the special interactions video
Faces... Fading in the flames... It was all her fault.
At first glance it seems like there's nothing special about this quote; I mean it's JINX, she kills and stuff for fun, but I think it may go further.
In Jinx's lore, it says no one really knows where she came from. The older people of Zaunite remember a girl fitting her description, but she wasn't crazy like Jinx. Quote: "This girl was sweet and innocent, a tinkerer with big ideas, who never quite fit in and came to a bad end.
I'm confident that this little girl was Jinx, and that one of her "big ideas" accidentally started a huge explosion that killed her parents and many other people, which is why Swain says to her, "Faces... Fading in the flames... It was all her fault." Swain stole her memories and KNOWS she felt remorse that day for killing her parents.
This ultimately made Jinx insane and enabled her chaotic nature.
There are a lot more clues that indicate Jinx accidentally started a fire in Vi's lore (and I'm sure we all agree by now that Jinx and Vi are sisters).
Quotes from her lore:
Vi remembers little of her childhood, and what she does remember, she wishes she didn’t.
None of the old timers from Vi’s youth could tell her anything of her parents, with most assuming they had simply died in one of the industrial accidents...
In the end, Vi gave up on any notions of learning anything about her parents, figuring some things were better left unknown.
Jinx killed their parents.
Jinx also knows Vi is her sister (but Vi doesn't know about Jinx). In Jinx's lore she only targets Vi in all her recent crimes. Perhaps it's because she feels guilty and this is either
1) A psychotic way of apologizing 2) She wants Vi to kill her because she's so guilty of killing their parents.
There is one small problem with this theory though based on Vi's lore. It says,
On his deathbed, a notoriously mad sump-scrapper claimed to have found Vi adrift in a bassinet large enough for two in the ruins of a collapsed chem-laboratory.
This implies that he found Vi as a baby, which may mean Jinx was a baby at that time too since the bassinet had room for one more baby.
I don't think this is too damning though. For one, it says the guy was notoriously mad. I believe he did find Vi in a collapsed laboratory (where jinx started the fire), but the details he remembers are hazy.
It's also possible that Jinx is the older sister and was old enough to tinker around with gadgets, thus starting the fire. She might have even saved Vi during the fire.
Edit 1 - Madnessfuel (comment is somewhere below) informed me that a Rioter did confirm a long time ago that Jinx is the older sister.
Edit 2 Also HandsomeTaco's comment below regarding Warwick gives more evidence to the theory!
Edit 3 (Kind of long. You can skip this unless you think Vi and Jinx are not sisters). There are a few people who are totally against the idea of Vi and Jinx being sisters, even though it's been heavily implied for the past 4 years. To be fair, Riot has never 100% confirmed they are sisters, but a Riot employee said they were siblings in an interview. He later said Riot has never confirmed if they were sisters, so he could be wrong.
What confuses is me how people could think they're NOT sisters. There's a million hints that they are sisters, but there's not a single hint that they are NOT sisters.
Here's what one Rioter said when Jinx first came out:
Vi and Jinx don’t behave like siblings at all! I mean, they’re always bickering and making fun of each other, and that’s not very sisterly, right? Actually, wait a minute… Perhaps this topic DOES merit some further consideration. So here’s what we know: Vi claims in Jinx’s teaser that she has no idea who Jinx is or where she came from. So if these two are related, Vi clearly hasn’t gotten the memo yet. Which is interesting, and there’s also the fact that we don’t know a whole lot about Vi’s past as a street urchin. So who knows? Seems like there are a lot of interesting story paths this rivalry could go down. I can’t wait to see how it will play out!
-Ok so if we go with the theory, it makes sense why Vi doesn't know Jinx.
-Seriously, why would Riot post stuff like this without some sort of meaning behind it?
-Shopkeeper in Howling Abyss says to Vi, "You look so much like your sister. Oh wait I'm not supposed to talk to you about that."
Not only does this add more fuel to the theory since the shopkeeper doesn't want to talk about the horrible accident, but also why would he mention her sister? Jinx has a line "You think I'm crazy? You should see my sister."
Again, why would Riot put lines like this in the game without any meaning at all? Why does Jinx only target Vi in her lore? I genuinely don't understand people could say "no they're definitely not sisters." I feel like if you say that you're purposefully ignoring the clues.