I mean, Yrel has solid tankiness.
She also has a decent amount of peel, able to talent into a continual 75% slow, as well as having a baseline knockback+stun in her kit.
Of course, her peel also requires her team to play around her - If a squishy is being dived, a Diablo can just point-n-click, a Muradin can leap-n-stun, ect. A Yrel, though? The squishy has to go TO Yrel to get peels.
Also, Muradin, a very popular tank atm, hard-counters Yrel.
Yrel’s own strengths kinda counter her too - She has the highest AA damage amount tanks, sitting at 120 dps. However, she can’t get the full damage of her kit out, ever - If she fully channels an ability, she misses AAs. If she uses abilities quickly to maximize AAs, they aren’t at full power.
There’s also the fact that her abilities go on full CD when interupted - No other cast time/channeled abilities in the game are like that. If you interupt a Chromie’s Q, Azmodan’s Q before it goes off, it does not incur a CD time. Sure, Azmodan’s E is on CD (And is pretty much the only non-heroic channel I can think of), but it’s CD starts on channel start, NOT channel end (So if it goes all the way off, it’s 3.5 second CD, unlike Yrels who can channel for 2 seconds, and then have a 6 second CD anyway)
So, Yrel needs a few small tweaks to her kit imo to climb out of the low-40% winrate.
One - Increase in AA damage AND Attack speed, proportionaly. Make her AA more resemble Stukov’s (240 damage/hit, 2 second swing time)
Two - Ability CD starts on channel start, NOT channel end. While this will allow for significantly more ability usage on Yrel’s behalf, her high mana costs will help to curb that.
I mean, really, that’s it. With those two buffs, Yrel will NOT be countered anywhere near as much by CC as she currently is (Exception of Muradin), and she will be able to maximize her already high damage output.