Apologies if this isn't the right place - please redirect me if so.

So, the community seems to generally agree that Arcanist as a class is pretty OP. It provides buffs and debuffs more concentratedly than ever before (primarily taking the power of Minor Courage out of support 5 pc sets and into a single arc skil), and probably most disruptively, has become a top tier choice in trial content due to having extremely strong cleave damage on a simple rotation. The challenge to balancing this, I expect, is that arcanist is such a "do everything" class that numerical nerfs or buffs are at risk of being all or nothing - either it becomes a jack of all trades and the weakest pick for all of them, or A master of all trades and outclasses everyone else.

I don't have answers to all these issues, but I do strongly believe at least the cleave problem can be solve, and it is the most distinct difference from other classes right now. I think the trick is to differentiate the single target vs AoE damage of Fatecarver by adding modifiers to different Arcanist class skills. This has the benefit of allowing "backwards compatibility" in terms of build - the classic simple rotation (flail, flail, beam) will still be a powerful cleave, but we can narrow the massive gap between cleave damage of Arcanist vs other classes whilst allowing Arcanist single target to remain competitive, *and* narrow the complexity gap so that arcanist still gets a satisfyingly powerful single target book beam as a greater reward for pressing more than 2 buttons.

Here is an example bundle of changes. The specifics can of course be tweaked, but this example should illustrate the strategy I suggested and how it moves towards the goals mentioned - maintain class identity and feel while allowing players to invest in more complex rotations to achieve competitive single target damage:

• Reduce Fatecarver damage values by 15%. This will be given back to the beam for specified targets via other skills (and a little bit more, to compensate for having to spend the time on the other skills, and for competitiveness with other classes).
• The Imperfect Ring causes the initial target to take 8% increased damage from Arcanist skills. This is a no-brainer candidate for restoring single-target Fatecarver from previous bullet point - meshes with "all-in" Herald of the Tome theme like its last passive, and 20 second duration fits seamlessly into existing Arcanist rotations. If this were the only skill to restore Fatecarver damage taken from point 1, I would bump the 8% to 18% (1/(1.00-0.15) = 1.76). This would of course boost flail damage as well.
• Rune of Eldritch Horror and Rune of Uncanny Adoration cause the target to take 8% increased damage over time from you. This is one I'm unsure about, as it is a little off-beat to gate a powerful DPS ability within a "tank" skill tree, but this is not strictly disallowed - after all, base game classes had skill trees more split by flavor rather than role. "Tank" breaking aside, this hits a few design minigoals in addition to being a "filler" to restore Fatecarver-nerf-damage:
  * gives the Arcanist a short-cooldown skill, analogous to NB arrow, Sorc bomb rune, Templar bomb light, DK talons, Warden shalks, and Necro blastbones (RIP).
  * rewards Arcanist more for DoT uptime like with other classes.
  * adds meaningful decision making to the morph, since Colorless Pool is far and away the better PvE option already for Minor Brittle uptime. This gives Arcanists a reason to pick the other morph in PvE (DPS arc vs. support arc)

Again, this is one example of how to take the strategy of nerfing beam cleave without taking away beam ST satisfaction, with tweakable numbers. A more ambitious approach could modify existing skills more heavily to allow single target focus, like Cephaliarch's Flail applying super-strong ink to the nearest enemy hit, or changing one of the heal skill tree skills to somehow target an enemy (like a Chakram morph that hits enemies and causes them to grant shields to nearby enemies and also take additional beam damage).

Secondarily to all that stuff above, it is often noted that some abilities do way too much on a single button press. Cephaliarch's Flail is the worst offender - heal, execute, AoE, debuff enemy for more beam damage, generate crux. I think a fair balancing act would be only granting effects upon actually hitting an enemy (which is how I initially thought it works, anyways). Pre-casting tentacles during downtime/invuln phases is a bit too strong, allowing easy heal while frontloading beam charge when enemies become targetable. To compensate, one could add some reasonable self-heal to other arcanist skills, or give no compensation at all (since one could simply slot a real heal skill in the meantime for self-heals). Personally, I use Runeguard of Freedom as a fake self-heal already (another loaded skill), so if it's technically feasible, applying the self-heal before the damage calcs (or before death check occurs) should be a nice minor compensation for the flail nerf.