Blood for the Baron!

Vypra's original filecard said she was Ann A Conda, a driver born in New Orleans and raised in Florida, while a later release of two Vypras depicted them as the twin daughters of Onihashi, the swordsmith for the Arashikage clan, and the twins were the guardians of some ancient swords (despite the figures still being labeled as ).
Okay, they could be just different characters (like the Long Ranges and Croc Masters), but what about reconciling those backgrounds?
Maybe Onihashi lived in New Orleans for a while, married and had twin daughters, but some enemy of the Arashikage (maybe the Night Creepers) found Onihashi and he asked his wife to hide with the twins to not be trapped in the way of harm. Onihashi returned to Japan while his wife re-took her maiden name (Conda), escaped to Florida and raised the twins. Ann grew up as the "bad twin". Many, many years later, the twins went to Japan to meet their father, since Ann felt she was ready to take care of herself and dragged her sister with her. Onihashi trained the twins and gave them the labor of guardians of the Arashikage swords, with the shared name of "Vypra".
The twins never knew their father would die shortly after, commiting sepukku due to the betrayal of his disciple .
When tried to get the swords, Ann was tempted by the power had to offer and betrayed her sister (maybe even killed her), joining as the only Vypra remaining.
Now, I don't know how to add her driving skills to the mix...

interesting theory, though would the transfer not be the other way around, from the Rattler driver to defender of the swords?

You mean due to the figure order? Okay, there's an alternative take:
The story goes the same til the part of going to Japan; only Ann's sister went, and Ann herself trained with an unknown master (the original filecard still mentioned martial arts as her secondary speciality). Some time later, recruited Ann with the codename Vypra. Years later, after World War Three (when she fought Jinx) and 's imprisonment, Vypra sought for her sister, who now was the swords' guardian, and joined her in that labor as her path to redemption.
I still like my 1st version more, but here's the alternative.

cool, Larry Hama eat your heart out

there should be a movie set around the Onihashi years.

When did Vypra face Jinx, and who was victorious?

That happened in a single panel of America's Elite #32 and the victor wasn't revealed. In fact, that was the only in-person appearance of Vypra, after a pair of issues mentioning she being followed by :snakeeyes: and and later her name at the list of Coffin escapees in #31

I see, I'm a few issues short of completing that run, refuse to read any till i have them all.

might be some time before I get the last few at the current rate.

GP the trade is available look on Amazon for it.