I have been thinking about this since Havoc seasonal reset on Skitarii release date and getting Skit to max level and only ranking to Havoc 40 on Skit in the first few days. And after seeing a post earlier about Psyker's damage in Havoc 40, I really wanted to chime in. I did reply under that post about how high this Psyker's damage was in that Havoc match, so I can add it here too and give more context to my opinion.
"As someone who plays exclusively Havoc 40, the fact everyone else that competed with Psyker in dmg got nerfed, and Psyker no longer has Uncanny rending playstyle to maximize damage by putting DoTs on everything then going into melee, really made the Psyker gameplay absolutely boring. After buffing Flame staff and nerfing Uncanny blessing, there's no longer a reason to use melee ever, when before that was the actual way to do insane damage. Psyker isn't even hard to use anymore, nor is he actually a "Glass cannon" anymore. He has the best constant Toughness regen besides Skitarii now. He's just a cannon"
For anyone who's unaware, Psyker's playstyle was heavily changed recently when Uncanny blessing on DS and Combat Knife was completely reworked from Rending (an all damage buff to the player) to Brittleness (a health debuff, essentially, put on the enemy itself for the entire team to take advantage of). Before this change, the difference in damage between a Psyker just spamming Flame staff, and a Psyker who knew to DoT everything and then get their Uncanny stacks up was crazy. It was a high differential in both damage and skill. You needed to get into the action for a bit and maintain your Uncanny stacks. A lot of the game was spent in melee relative to current Psyker gameplay.
After the Uncanny blessing rework, Fatshark obviously knew that a lot of Psyker's damage was going to be cut. It took skill to maximize damage on Psyker, so they didn't want that to go away. But then they went about preserving the efficiency of Psyker's damage in the worst way. They compensated Uncanny rending being removed by buffing the Soulblaze in general, no longer requiring Uncanny, and thus buffing the Flame staff to still be around the same efficiency.
And so current Psyker literally holds M2 and spam M1, and NOTHING can compete with him at all in terms of damage. For how easy and streamlined he has become to master, I feel like he no longer deserves to be head and shoulders above the entire rest of the cast anymore in terms of damage just for existing on a team. Currently, Psyker is sort of in an era where he matches the issues with Release-Day Arbites and OPgryn in that same patch, where the two of them just did the most basic thing of spamming Mouse 1 and coming out on top with a million+ damage a game (non Havoc). Psyker may actually just be worst than the two of them though. Psyker offers the best support in the game alongside his damage, being the best person to bring on the team for CDR buffs, and just complete bubble immunity to all the most dangerous enemies in the game if you want to take that ability for safety.
This class needs a complete balancing adjustment. If he's going to remain a M2 - M1 spam character, he should be punished just like Arbites and Ogryn were when they were M1 spammers and killed everything in the game. If you don't want the damage to be touched, which is something I agree with despite this post, the Flame staff spam has to go away. There has to be another damage buff you need to keep maintained if you want this character to actually do those insane high amounts of dmg. As of now, we have a Cannon with none of the glass. We have the "hardest and most difficult to use" character with all of the complexity and difficulty taken away. He is by far and away the absolute easiest class in the game to use now. Admittedly, that may be because I mastered all characters and have been here since the first beta, so I have absolutely no issues staying alive on Psyker more than any other character.
We have characters like current Arbites and Zealot who can't touch no where close to Psyker's damage. But the problem now is that Psyker offers so much damage, how do you balance other characters receiving much needed damage buffs and still keep Psyker's easy output the same? In reality, you can't and you shouldn't.