Kalista + Galio divebomb.
We did that one and Kalista+Pantheon - both were very fun
Kalista+Vayne do crazy damage together, just insane - while Panth is able to play slightly more supportive with stuns / passive - and Kalista can huck him into the fray to overcome kiting - also Kalista's W passive combo works really well with Panth's spear during execute. Both are fun combos, but obviously not super viable.
What route have you guys gone when building her?
I usually go IE - Shiv - BT/LW - BT/LW - X
I tried building BotRK on her first instead of BT, but the attack speed got way too big for me, so i was constantly messing up my passive, and ended up dying. As for skill order, i like to max E first. Not sure if it's better than Q, but i like using it, pretty much the same as Twitch's expunge.
I had the same problem with BotRK+Shiv builds, I think you need to go one or the other - personally I prefer Shiv for the movement speed (since she's really slow without her hops).
Same build as you though - Shiv -> IE -> BT/LW -> BT/LW -> Something Defensive (Spirit Visage or sometimes Randuins)
I find it funny how her passive basically destroys the role of brusier unless they're double dashers.
Tbh i don't think her passive is that problematic. If pretty much any bruiser gets to her and cc's her, she's dead. She's so fucking squishy + the passive doesen't count for shit if you're slowed.
im a lol noob played it on and off for about a year ( only lvl 12 ) and i saved up the ip to buy kalista and although i have no idea how to play her properly i love playing her lol, before i use to use master yi but now i have kalista i play her in every game. although her passive is kinda annoying trying to move the camera aswell as use her passive as well as making sure im far enough away from the enemy. just feels like i need to do so much at once and if i make 1 mistake ( usually i do because im a noob xD ) its insta death for me my KDR is pretty bad lol http://www.lolking.net/summoner/euw/40692475#matches
Also holding shift + right clicking will make using her passive a joke pretty much. Providing you aren't fighting next to minions ofc, since she attacks the nearest target if you do that.