For the sake of the games health, these two abilities need to be reworked, and the key word here is to be reworked, not nerfed, and then given compensational buffs or anything like that. 
These abilities are simply way too strong for 5 vs. 5, and this isn’t something new by any means. I’m just bringing this up now because, I don’t know, I just feel like making a point and rambling about something. Lol
Ana
Listen, tank players should not be expected to have one of their teammates switch for them, in this case to Kiri; otherwise, they can’t play the game. That’s completely ridiculous.
“Yeah, it’s so ridiculous to expect teammates to play around you in a team-based game.”
This ain’t lala land brotha; players are selfish and couldn’t give a damn that Granny’s puting it down on you; hell, they’ll probably start flaming you in chat right after the game ends, even though the loss is on them and it’s their fault they didn’t switch to counter the nade. That’s just how it is, and it is terrible. (Nade is the pinnacle of poor balancing in Overwatch.)
How do I think they should rework it? They should change it into a zoning tool, but, of course, keep the overall concept of the nade the same. Instead of Ana throwing the nade and immediately having an effect on the target, now, when she throws the nade, it creates a puddle on the ground, where if allies or enemies are standing in it, a healing percentage increase or a healing deduction percentage will build up over time until the puddle effect ceases.
Zen
Now, let’s talk about the stinking mammoth in the room, the robot monk. Either his discorb orb is completely useless and doesn’t provide any meaningful utility for the team, which in turn makes Zen completely useless because all of his value is coming from his discorb orb (I was going to say his trance brings a lot of value, but now with the new DPS passive, you can actually cleave through it, so no, not really anymore), or his discorb orb is completely busted, which makes him unequivocally the strongest character in the entire game, like we’re seeing now.
Characters like Zen, where you’re either the strongest or worst character in the game at any given time, are huge red flags and should be reworked to have their power more proportionally spread out through their kit.
Also, he makes tanks lives a living hell, so there’s that. 
How do I think they should rework his discord? I honestly don’t know. It’s way more difficult to come up with an idea for how they should rework his discord because his hero identity, which is a peaceful monk, is in direct conflict with what everyone has come to know him as today, which is a bootleg DPS glass canon. At the end of the day, though, as long as the Discord orb is punishing the initial target he’s put it on, I believe that’s still in line with Zen’s hero identity.
My best crack at it would be to change Discord orb, so it now converts damage dealt by the discorded target into additive healing for the player with harmony orb on. This is playing into the idea of what Zen is, more lore wise, a peaceful robo monk, where now his enemies will be punished not through conflict from Zen himself but rather through their own actions. I don’t know, I tried. Lol
Anyway, I hope you had fun reading all this rambling. That is all.
Good day!
