There any chance you'd reconsider on Kalista's ult..?
It's honestly a toxic thing to bring into the game player-wise. What do I mean by that?
Someone uses it for flat-out trolling purposes. Rage-fest.
Someone uses it poorly. Rage-fest.
Someone makes a gravely mistaken miss-click. Rage-fest.
Someone's butthurt it got used on them because they were about to do something. Rage-fest.
Someone uses it at all, all the sudden- rage-fest, entire fight loss gets blamed on the person who happens to be playing Kalista.
Anyone who plays Kalista is going to deal with rage, and a lot of it, just because of the nature of the ult itself. You don't have the greatest track record for reverting pretty big things, but I really really hope you re-consider, mainly because of all the rage that will happen.