This is a more reasonable version of that “remove 1 character” thread.
As Hoku pointed out, “Every hero is loved by someone,” so outright removing a hero would be unfair.
It would also never happen.
So instead of removing the hero, what is one hero that, if you could, you would permanently block from being in your games?
Note that this would prevent you from playing that hero as well.
Thrall 20 characters
That’s a bit of a surprising choice, actually. Any particular reason why?
Probably Imperius 
My answer remains still none, because this basically another ban and people would just ban meta heroes or heroes annoying to deal with. This would punish players, who pick this heroes as their mains or want to play them, but they have to wait longer for games. Quite unrealistic.
Murky! Stop the Murky abuse!
As a Murky player I feel offended…! Now I would have longer queues, because there some players who hate Murky. 
I’m thinking it’s like the “remove 1 hero” thread, where you permanently lock in 1 hero. You can’t change your pick (unless they’re reworked, I suppose), so you’d better make sure you spent your pick wisely and not on some flavor of the week/month impulse.
3 years ago? Varian for sure
Still none, because I don’t care about any hero. All heroes can be annoying, when played right, but I don’t feel that I need to perma-ban one.
In the past, where I was less good I would say heroes like Zagara Probius, TLV or Rexxar, because they feeled less uselful for team battles and mostly do their thing alone. But I realize now they are far away from being “useless”, they are just different in playstyle and might be harder to get the value from like other heroes. This why I can’t decide what to remove or perma-ban.
I am still confused how bad players treatning Nova as “useless”, when she is basically a “noob killer” of a hero. But it is probably, because most people like aoe and stun and that’s why KT is probably perma-banned.
Btw I have my pick while I am in low elo (silver): I would ban KT. So I can use my bans for other useful bans. 
But here is the thing I also like playing him, but then he still wrecks my games, when enemys get him…
Don’t consider what anyone else wants, and assume you’re the only person who gets to do this so queue times will remain basically the same.
What is the one hero that you would most rather never see in your own games again?
Brightwing
For being tied with Arthas as the worst out of Qhira’s unholy six, and since Arthas has a hard counter that makes me grin that I love playing almost as much as the Huntress (Zul’jin) it’s brightwing for sure.
Garrosh.
I’ve been keeping him perma-ban for 3years.
Think I’ll go for the same choice as well.
Garrosh forces you to play safe the entire game just by existing.
After a certain level (usually 13 or 16), even someone like Muradin (with e available) can’t survive being thrown.
Doesn’t matter that he’s statistically balanced, you have to play lame to win against him basically.
All the fun heroes are hated. Murky, Nova or Garrosh. #Feelsbadman.
Genji - until deflect gets changed so that my idiot team mates cant kill me because they dont have the discipline to not AA for 1 second (or the braxis boss for that matter).
No other hero to this day since open beta gets me tilted like Genji into Tracer/Tassadar/Tychus/Dva.
If only one - Qhira.
Reason - doesnt belong in HotS. Feels like generic OC diversity League of Legends hero. Not in any blizzard universe. Not even balance related in any way, I just dont like her.
Next one would be Orphea (same reasons)
Then every OW hero except Genji, Hanzo and Ana (these are good)
Reason - attack while moving mechanic does not belong in MOBA (Tracer, Dva, Lucio), and Mei should have never been added and Reinhardt should be here instead.
Nooooooooo! We ban Murky to safe Murky! The Nexus has too many Murky deaths!
Hammer! I hate that hero so much.
I would ban the top ranged dps of the moment i think