@SmashGizmo @Meddler @Riot Solving the Kalista issue by changing her role to Support
As someone who plays Kalista Support because i hate playing meta and it actually works fairly well, these are my thoughts.
Kalista is hands-down the best ADC when it comes to supporting capacity. She has decent poke, some mobility, interactive bonus damage in the Soul Mark, free vision/ways to reveal enemies from a bush, a slow that can be applied to more than one person and technically can't miss, and a get-someone-out-of-jail-free ultimate that could make just about any other support jealous. I say if Kalista can't be balanced as an ADC, make her into an AD support.
It still fits her theme and lore as someone who aids people attain vengeance, and it fits her current kit almost perfectly.
Support-Kalista is currently held back by three things;
1; The inability to trade Oathsworns. Sometimes your early game partner either does not need your help or someone else's skills could be better used. Putting the Oath on a 15 minutes cooldown before unlocking or something may be nice, even though it's ultimately unnecessary.
2; W Soul Mark damage applying for herself instead of for whoever's with her. One way to solve this problem would be to give the damage to whoever of the two partners has highest AD at the moment of the proc, that way people can play her either ADC or Support and the passive still works as intended.
3; Itemization. Kalista's choices are obviously fairly limited. She can build somewhat tanky and function as a more or less traditional support. However I've found that on-hit effects like Wit's End, Black Cleaver and Frozen Mallet, aimed at weakening the enemy team, are actually really nice for any would-be AD support.
Granted creating a major shift in Bot Lane by introducing an entire new cast of would-be AD support champions sounds troublesome, but i believe that if any one single champion was ever fit for the role, Kalista is the one. She just needs a couple of tweaks such as her Q applying on-hit effects (not damage), and she could become a legitimate pick for the Support role.