Hi there! I am a Silver 4 AD Carry main. I don't play ranked very often, I prefer to play normals for fun. But I put on big boy pants on and made this very serious pro build.
"Our retribution shall be swift." ~ Kalista

Pros

+ High kiting potential
+ High Mobility
+ Great poke
+ Great Chase
+ Amazing engage
+ Amazing teamfight
+ Self Peeling
+ Easy to Farm
+ Easy to Learn
+ E Damage beats max smite late game

Cons

- Squishy
- Long AA Wind up early game
- Extremely hard to master
- Can not cancel auto without Q
- Escape/Mobility requires AA or Q
- Requires communication with R

Passive - Martial Poise
This passive is the main point on Kalista. You can chase, kite, escape, and juke with this. This is also why we rush bork. The downside to getting a free jump every auto, is you CANNOT cancel your auto, unless you Q. Your auto will also not go off if you lose sight of the enemy, making your extremely vulnerable at early levels. Pro tip: Use shift click (Attack Move w/o indicator) to control passive easier.

Q - Pierce
Use this to proc passive. I would recommend taking a seocnd level in this ability early because it increases the base damage from 10 to 70. This is a great way to get a rend stack on a target, then using rend to get the slow so you can catch up. Note: This skills missle/aim is slightly off. Play around with it to get the feel.

W - Sentinel
So this right here is Kalista's laning phase. Her W passive gives her 12% magical damage on hit, plus whatever skill you or your laning buddy used. It's increadably strong, and is very important that you abuse it in lane. Tip: Have your support use a ranged skill to get the initial proc off, then follow up with a Q to get an easy W passive proc.
The active portion of her W is a moving ward that can only see in one direction. If the enemy sees you place it, they gain vision of it permanently! Even thru the fog of war, and mini map!

E - Rend
This is Kalista's execute and slow. You can use Q to get a stack of this onto the enemy while moving closer to them with passive, then E to get the slow off so you can chase, or jump the opposite way to get away. Huge poke combo: Hit a castor minion 2 times with autos, then auto and Q their ADC, hit E to do a lot of damage, then auto again and E because you got E reset. Lots of damage, lots of slows.
Tip: When taking an objective like Baron or Dragon, your E will beat smite at ~20 stacks!

R - Fate's Call
Basically, just initiate with this, or use it as an escape since it makes your ally invulnerable. When using it with a ranged person, it's like a Quinn E. It will go to wherever they send themselves at, then it will knock them back to their max range.

9/10 you're going to want to get this item first. Even when you don't, you still pick it up. If you're getting really ahead, definitely buy this item. If you're really behind, I recommend picking up the Infinity Edge. If you aren't sure, just play it safe and pick this up. It's really strong on her because of the Attack Speed, the Slow Active, and the on hit effect. This makes her mid game strong!

This item is better on Kalista than Phantom Dancer until you're full build with Elixir. Yes, you might not get as much attack speed until PD, but you get the huge nuke with the passive. When you go in and knock their ADC/Mid down to half health with an auto, you'll know exactly what I'm talking about. Plus, this gives her wave clear and extra needed damage to burst people.

I'm not going to put much work into this chapter because Kalista works well with pretty much anyone. As long as you bind your laning buddy, you'll do fine. Even if you ult them into the enemy team, it's like a Quinn E. It will just bounce them back to their maximum auto attack range, making sending a squishy Karma support into their entire team a good idea. You can also bind someone that isn't your support. For example, if you have a J4 or something, you can bind them for the 4 MAN ULTI WOOOOOMBOOOOOOO.

In the League of Legends Champion Spotlight, featuring Kalista, Phreak discusses a few tactics. One of these tactics is to auto attack a minion once or twice, then engaging in a trade, autoing a few times, then E'ing, autoing + Q, then E'ing again because of the reset. It's a lot of damage, and can be reset an infinite amount of times. Also, that video has a lot of tips I'm not going to go over because they're in that video.

Play Video
USE SHIFT CLICK (You can bind it in game as "attack on click") TO PROC PASSIVE REALLY EASY!!


Use E on Objectives like Dragon and Baron to beat smite! Your E will do 1200-2000 damage with your E, depending on the stacks. At around 20 stacks your E will beat a max level smite, assuming you're fill build.


Targons + W Passive = D:
If your support wants to proc her/his Targon's Brace on the minion, don't auto it. Just wait and be patient! YOU'LL GET YOUR DAMN HEALTH AND GOLD LATER.


Use your Q outside of combat to go over walls.


DON'T FORGET ABOUT YOUR ULT FOR THAT 5 MAN ULTI WOOOOMBOOOOOO
In all seriousness, use this **** for engages. It's OP!