[2022] Sledge protean is not balanced for solo.

Here's why:

1: The armor is only on the front, but he's ALWAYS facing you. When Sledge goes into his armor mode, the armor is only on the front, which is great for co-op because one teammate can kite him while the others shoot him in the back. In solo though, he's always facing you, meaning you never get the opportunity to shoot him in the back unless you stun him. Which brings me to my second point.

2: Stuns don't interupt his attacks. Whenever Sledge is charging an attack or is in the middle of the attack, teleport, or any other action, you can't stun him out of it. This is combined with the fact that the windows where he actually is vulnerable to stuns are very, very small. He will transition straight from a teleport into an AOE attack with absolutely no downtime inbetween, meaning that the windows to actually make him vulnerable are few, far between, and really short. Assuming you can stun him, you run into the third problem.

3: His stun time is really, really short. If you do manage to stun him, he's only stunned for like a second, meaning you have virtually no time to capitalize on the stun, especially if he's in his armored mode where you need to run around and shoot him in the back.

All of these things combined make solo-fighting the Sledge protean a rage inducing experience. Addressing any one of these particular issues will make the fight better, but I'd recommend a combination of them. A must is either having stuns interupt actions or having armor breakable. Otherwise this fight is just unfair for solo players.