So in short you want that warlock would be wizard??totally agree with idea of SW being unique in its role - focus on dps, not mimic some other class with CC etc.
Soulweaver is good example what happens if you try convert one class to do what other class do..
Soulweaver powers mimic/copy what paldin/cleric powers do.. And how it ended up?? Well, in mod 16~17 soulweaver was brushed aside as irrelevant class.
Cleric have higher magnitudes and can regenerate divinity by holding TAB.. Warlock can't do that... Also warlocks barrier override other shield and even own barier...
So in attempt to mimic paladin shield all get messed up...
So do you want same outcome for Hellbringer ( dps) warlocK??
If you have two or more classes who does same thing in same way,, players will pick one and discard others.. Thats general rule for all mmo rpg games.. That's why all classes are build to have slighly different play style, at least if you want to make them relevant..
Also just think for moment,, if you have warlock who does same thing ( CC fiesta) and wizard does same thing.. Then one class get picked by players and other get sacrificed..
That is not a balance..
Quick story about warlock... When it was introduced in mod 4.. ( hellbringer path). Unlike Wizard who had lot of CC, x4 encounter slots and fast casting. I t had massive damage per hit, longer cool downs and curse (legacy tab mechanic) to boost up dealt dmg further. But also in exchange warlock lacked CC.
And in that time, we lacked CC for real.
We had only 2 CC encounters, warith shadow ( legacy) and Harrostorm( legacy)..
Harrowstorm.
https://neverwinter.fandom.com/wiki/Harrowstorm_(SW)
Aoe fire dps, and if apply curse ( legacy tab key mechanic) dps effect converted to single target CC...
For most time, it was unpractical to use this encounter for CC.. And even for dps was not so grea, cuz you could not boost up dealt dmg via curse..
And second CC was, Wraith Shadow -
https://neverwinter.fandom.com/wiki/Wraith's_Shadow_(SW)
You apply curse, then cast this encounter and then recast/activate it. And you get ~1.2s AoE CC. And all casting time to reach it was like 4s. So 4s to get 1s CC.. That was a suicide in pvp.. And also to call it AoE was more a joke.. At best 3 enemies get CC nothing more.. But even this CC was like tiny/mini lag spike than real CC..
So as you can see, at that time we indeed lacked CC..
The Arm of Hadar and Hadar Grasp were added in mod 6. When lv cap got increased from 60 to 70 . And after life steal ( legacy mechanic) nerf warlocks was in so bad postion, that roughly 80~85% of all warlocks either quit game or moved to other classes.
So developers added additional CC abilties..
Now Hadar Grasp story is very simple.. It is coppy of Wizards Etangling Force encounters... But in excahnge of that, wizard got DIsintigrate which if you notice using kinda same mechanic as warlocks killing flame encounter... Cuz at that time wizard lacked strong dps powers...
And as for Arm of Hadar its simply attempt to mimic same effect as wizards legacy encounter Shard of the Endless Avalanche.
Then main thing was that Warlock lesser CC but more dps.
Wizard more CC but lesser dmg..
So do warlocks lack CC?
For Soulweavers I think could be done. But not just bluntly add CC.
Here is example.Lets take Wraith Shadow- Rework so it would use same aim/target mechanic as Hellbringer warlocks Hellfire ring ( cast to pointed area).
And instead casting hellfire, soulweaver would cast pool of shadows, which would use Spider web mechanic.. That's mean slow down enemies within it's effect area... Also syphoning enemies HP and restoring alies HP..
KInda Vampiric embrace but work as DoT..
Also as for consideration can be added that affected enemies would also do reduced damage.. So it would be usefull not just agains adds/trash in dungeons, but also would be usefull against CC immune enemies like bosses or golems...
Also it's free of Soulweave use, Aka regular cool down and etc.
Now as you notice, I made it locked for Soulweaver only, so it will not make different for Hellbringer..
Other thing this mean this encounter will give additional healing power which would not be locked to Soulweave mechanic( rescource).
And main thing is that thing encounter would provide heal/cc but in slighly different way as how other classes do..
The reason why temptation warlock were popular is not due insane healing.. Paladins could reach similar healing anyways.. But cuz it was doing all in different way then Cleric or paladin. It was healing via dps, and supporting via debufing.
With mod 16 it was attempt to rework Soulweaver to do healing in same way as how cleric/paladin do.. And it was whole reason why in mod 16~17 was pushed aside and irrelevant class.
Why play with clone who try mimic something, if you play original anyways???
Also adding more CC to Hellbringer, it will not make it do more dmg... Instead try look way to match up x class in dps, make sure that x class powers work how it should in first place. Cuz otherwise any attempt to balance broken class is nothing more but try build house on quicksand. Good attempt but always end up in bad way.
I understand that ohh but Warlock seems doing less dmg.. I see that. While this game is not my main does not mean I do not log in time to time. To check whats going on..
And I can assure you, the whole reason why wizards does massive dmg, why rogues does massive damage and even ranger and bard can do big dmg, is cuz some game mechanics are broken.
And one mechanic actually is also responsable why there are times that players got oneshoted.
But if devs fix these game mechanics, all class balances issues with reset. And all will start fall in their suposed postions..