Jason Freyr's Links
Jason resents Freyja for (in his mind) having a better childhood, but he also sees a lot of himself in her. In fact, Jason actually kind of likes and appreciates her a little. But on the other end Freyja barely tolerates him and he gets pissy at people who don't like him, so not much of a bond can be forged there.
Freyja doesn't have much of a relationship at all with her twin, and they do not get along that well like most feline siblings. If he died though she would care to some capacity, so at least there's that.