is this spell working as intended? why did it go from doing absolutely nothing to frequently one-shotting both friend and foe alike?

and this isn't me using it, the AI is using it on groups of both my allies and their allies and everyone gets hurt. so the AI does not seem optimized to using this skill as it currently exists, since its behaviour is the same as before when it only targeted enemies

frequently, an enemy will use it on a group of people and end up killing its own allies (as well as hurting mine). all of this leads me to think something is seriously wrong

I don't think the skill works as intended at all.
The fextralife wiki mentions this:
"Despite not being mentioned in the description, when cast by player characters, this skill appears also deal an initial hit to all characters in the area that varies from 100% to 250% weapon damage. As such, this skill is a very strong AoE ability for its AP cost and short cooldown."

Now here it says something about pcs, but as you mentioned the AI casting it actually has exactly the same effect.

In my humble opinion, either the tooltip is rephrased badly or the skill is totally broken. I guess it's the second option. When I encountered those archers with this skill, it became quite annoying.

It's totally broken. It used to not hit for initial damage but with the last patch it does wayyyy too much damage.

I paused my own play-through because of this issue (and yet another bug with Tarquin) The skill was great before, imho, now it's just unplayable . There are plenty reports about it on steam and here, I wonder what is taking them so long to fix it

Yeah its broken lol, enemies use it and kill their own allies even when im not there because they think i might walk there. They look so stupid its hilarious. Also if an enemy uses it why do we get to see the circle so we can just NOT walk into it? O_o

it's hilarious. It's basically like a free Arrow storm, just weaker. With Deathwish and high ground.. it's absurd.

I think it works as it should, just the description is woefully inadequate.
Why would you waste 2 AP on casting a spell that might or might not hit depending whether someone walks into it's AOE ?? Why don't you just go and cast Ricochet or something else and get the instant damage for the same AP ... This is what I thought would happen according to the spell description and why it took me so long to use this spell.
It makes total sense to do initial damage and give you a non-guaranteed chance for additional damage. The fact that it is AOE makes it possibly the best skill in the Huntsman arsenal.
One could combo in a party chicken, rupture tendons and reactive for some nice damage.

well, it's a 2 AP aoe spell which hits the largest circle aoe before arrow storm, has a guaranteed initial damage tick which does a lot of damage, seemingly far more than your regular weapon attack (which is what is used when someone actually does enter the aoe). it's already better than most skills you have access to at this point in the game

the "non-guaranteed chance for additional damage" comes (or should come) in the form of zoning off an aoe and discouraging enemies from entering it. currently though, its most effective use is simply dealing a lot of damage in an aoe, with the entry hazard effect functioning as more of an afterthought. this isn't what i imagine the creators intended when they created the skill

the issue to me seems to be that the skill was pretty bad beforehand, so it was buffed, but in the process of doing so something went wrong and it got overbuffed. on top of that, it seems like the intention behind the skill has been turned on its head

it also doesn't make any sense for it to hit allies. not even arrow storm does that

Pretty sure this skill got broken in the last patch, since before that patch, this didn't happen.

this skill appears to be working as it was before (as in, AI enemies are no longer one-shotting their teammates with it)

can't speak as to whether or not it works identically to the way it did before it became a mini arrow storm, but it's not wildly disproportionately strong anymore at least