when Kalista is stacking Rend it appears as a grey combat text so players know how much damage is stacked and when activated it turns to a red combat text to show how much damage was inflicted like how Garen's Judgment shows how much damage was caused when he activates it on an enemy champion.
Thats how much damage he does over the course of the ability.
What I think you're asking for is for her to have an indicator of how much damage it will do so she can tell when they're in kill range, which, nty, I think part of the skill of Kalista is knowing when Rend will kill.
So then what happens if Kalista starts attacking an enemy Tahm with his E up?
The Kalista Rend grey combat bar should exist as an overlay on the health bar, but only for the enemy team; not for Kalista. A Kalista player should have to approximate that, while a combatant should be able to gauge exactly how much damage she can put out with Rend.
That would be really helpful for tanks in particular, and it would be a good indirect nerf to a very strong ADC.
That's not a bad idea. I understand what you want. With something like that I would know how much of a chunk I would be taking out of them before I ren. It could also help the people against her. Telling them how much hp they will lose if they keep going.
also would help her cs. Cant tell you how annoying it is to fail to kill a minon
That's not nearly as easy as you think it might be. There is a difference between Tahm E and Kalista Rend: the grey health off Tahm marks already lost HP - post damagecalculation. There are plenty ways to change your defense values - you might suddenly gain armor so that you actually lose less health once Kalista uses Rend. Or the other way round, the grey bar would always need to adjust with every BC stack you receive. Even though it might be a good thing for clarity (for both, Kalista and the target) it isn't that simple.
Garen has it, why not others...
Would the Kalista herself be able to see this? It concerns me that then, they would know exactly how many stacks of rend they would need to have to finish off their opponent
I don't like it, simply because of the fact that it makes Kalista, a very powerful ADC, all the more reliable. She has to get other nerfs if you want this to happen.
This would be a huge buff to Kalista IMO
and I already hate her enough without her becoming an even more favorable pick
