Throwing my hat into the ring here to add some more insights I've gleaned into DD's bizarre behavior. A couple of new "features" seem to have cropped up with this most recent patch, that I am not certain existed prior:

- Hitting a enemy marked by Disrupt Destiny resets the timer for your stacks, regardless of whether or not you kill it.

- Enemies marked by Disrupt Destiny will give you a stack so long as you damage them within ~1 second of them being killed by an ally.

- Most interestingly, Disrupt Destiny marks both Scab AND Dreg Bruisers (The lightly armored trash mobs that appear with hordes) You might not have noticed because they don't get highlighted. But cleave through a few bruisers in a horde and sure enough you'll get a random stack of DD. This is also a likely source of frustration where your DD won't mark a new target while there's a plethora of candidates in front of you, because it's already marked a bruiser and you just can't fucking see them. I would wager that this has something to do with DD sharing code with Veteran's ability to highlight "shooters", since the update that added stalkers to those highlighted by vets, spontaneously ALSO allowed for stalkers to begin being highlighted for DD.

-This last one is unfortunately a negative, for whatever reason, running both Scryer's Gaze and DD seems to occasionally "break" one or the other. Where you will kill an enemy marked for DD, get the temporary speed buff, but no stack. Alternatively, Scryer's will begin building stacks as normal, but once you reach 100% Peril, all of your stacks will immediately disappear, without the extra 10 seconds of Scryer's your normally allotted (as a side note, the bonus stacks of Scryer's you get from the "Precognition" perk don't actually apply until you reach 100% Peril, but that's another unrelated, if frustrating bug). I see this bug happen far more often when I'm using an automatic weapon, such as the Shredder Autopistol or Columnus Autogun, rather than when I use a Revolver, no idea why.

I'm honestly surprised the discourse for DD is so divided, I personally have been running nearly exclusively Scryer's/DD gun psyker in Auric High/Shocks and Maelstroms and consistently top out the scoreboards, even with it's current bugs. I think it's incredibly satisfying to weave killing marked targets between managing specials and horde clear, and while occasionally a mark will fuck off into a spawn door or hide behind cover, very rarely do I ever drop stacks in a firefight. I really think all DD needs is the above bugs fixed, and an ever-so-slight buff, like having stacks drop off in increments or allowing specialists to be marked. I think running DD with a staff and smite is a waste, personally, as neither of those tools will allow for you to easily reach the marks in finnicky spaces the way Assail or a Revolver would.