Neat, thanks.
By the way, did you have any plans to buff PRM?
I had a PRM char around lvl 82 on HC a few builds ago before he died, and I felt the single target damage of the skill was pretty bad compared to other skills.
A breakdown of the skill in my eyes:
Pros:
- Good AoE damage
- Unblockable (and undodgable?)
- One of the few ranged missile spells without a cooldown
Cons:
- Among the highest skill point investment required (but the returns are not that great in comparison to some other attack skills)
- Relatively poor single target damage
- Elemental damage is also relatively hard to boost compared to single damage types (for my current char I intend to convert it to Aether for this reason)
- No weapon damage thus no native leech (major drawback)
- No WPS eligible nor other procs attached to it, so you can’t link more than 1 Devotion (second major drawback)
- Targeting clunky? (I’ve seen some other people mention this, personally I don’t have much of an issue with it though because I’m used to manually aiming)
- Very high energy consumption when fully maxed which requires building your character around as well
Having large investment requirements and high energy upkeep isn’t an issue to me: it gives the skill uniqueness, but it should be more rewarding for the player for handling these hurdles.
I think the easiest way to fix some of the issues is just to give it a damage increase at the higher skill ranks. Early & mid game it’s very decent even without any twinking, but later the single target damage starts to fall off due to con #3-5, so buffing its damage at that point would make sense.
Or buffing the ultimate ranks of the skill and its links by a significant amount, so you can use items to scale it further in the endgame.
Higher damage would also mean fewer casts necessary, which alleviates the energy cost issue indirectly.
I assume the game engine doesn’t allow you to make Proliferation eligible for Devotions, but that would close the power gap with attacks with WPS somewhat.
Or to allow the extra fragments from it to hit the main target as well, so the skill doesn’t lose most of its firepower when there is only one target.
That might be very strong so perhaps the damage values on the skill need to be lowered a bit to compensate.
Giving the Supercharged link some cast or missile speed would fit thematically, and give the skill a bit more oomph.
Another idea is to improve the items related to this skill, such as:
-Invoker’s set
-Paragon of the Arcanum set
-Blackwood Arbalest (I don’t see anyone using this, the 2h disadvantages are too big: without exaggeration I feel you could literally double the values on all its affixes and it would barely be competitive)
-Panetti’s Replicating Wand (I always liked the design of this item, and it’s tailor-made for the skill! However, the proc it has is useless for PRM, I thought it would be interesting if it has a missiles on attack proc like the above Arbalest item. It fits the theme of the skill and would add a good chunk of single target DPS if it had decent proc conditions and damage values)
Related to this, IEE has both a 100% chance for a random flat element damage, and a flat Elemental damage bonus.
Neither really benefits a caster Arcanist, changing the random damage affix to a % bonus chance to various spell damage types (Elemental, Aether, Chaos) would change that and make it worth leveling for casters.
Currently you just get the energy regeneration which doesn’t seem worth more than the first point.
And while I’m reporting bugs: the item in the screenshot seems to have a zero too many in the life affix. 
In reality, that isn’t supposed to be % Health but flat Health. We’ll get on it.