I'm not going to cry OP since obviously I've got a 1 game sample size, but what are immobile champs supposed to do about her? You can't run away because she can constantly chase unless you gapclose/flash out of her AA range and you can't chase because the same thing happens in reverse. Is the answer just don't lock in immobility vs. Kalista?
Stun/Snare/Root/Airborne
If you find your self against a kalista, you want to get your support to be someone who can shutdown kalista's movement with things to prevent her from moving around (like zyra plants or janna tornados). For the most part, you don't want to lock immobile against her unless your ashe, who comedicly has the exact same ability just with slows instead of leaps.
Early game, you can make her juke herself easily. When she's chasing you with hops, turn around and attack her as she hops towards you, so she'll dump herself in your lap. And if she's hopping away from you, turning and running as she hops can put her out of range with no way to get back close to you.
Late game, though, she has enough attack speed that this won't really work, and then it's basically a matter of which champ you picked.
Basically, Riot hates immobile champs, don't play them.
