As some of you might have seen, the Shadow 6-piece bonus is being buffed to allow extra Impale hits to get a 25000% bonus (the first hits still get the 75000%). What this means is that trash around the intended target will be worth more and the damage scaling in density changes from linear (assuming area damage and negligible secondary hits) to quadratic.
To make sense of this, if you attack 10 targets stacked up with say 100% area damage (in melee range so all 3 daggers hit), the damage (in terms damage without the 6-piece bonus) is about:
Damage (S24) = (3 + (10 - 1)*(0.2*100%))*101 + (3 + (10 - 1)*(0.2*100%))*9 = 528
where the 0.2 comes from the 20% area damage proc rate and the (10 - 1) term comes from the area damage applying to the 9 other targets.
However, in season 25, the damage will scale a lot more:
Damage (S25) = (3 + (10 - 1)*(0.2*100%))*101 + (3 + (10 - 1)*(0.2*100%))*9*34.333= 1968
Which is a rather large boost of almost 4x! If you then stack more targets, the relative buff is even more extreme! For 20 targets, stacked on top of each other, the S24 damage is 816 while the buffed number is 5122.33 (over a 6x boost).
Of course, this assumes every dagger hits all targets stacked exactly on top of each other, using the Overpenetration rune. For solo situations, I think Ricochet will be more desirable in most cases since a pull is not usually available.
Edit: fixed some numbers.