At this point, i’m not sure we’re going to get any further buffs to Horn of Gandarr’s damage/CDR. The last time it was pushed for (and happened mind you) was with the following post in mind:
Suffice to say, i think it’s in exactly the spot they want it to be - on it’s own it’s a superb support skill with it’s debuffs and with enough gear through the Rimetongue set and Codex of Truth, it becomes semi-decent for single targets but it’s not displacing skills with far less natural AoE but more nuke capability/high sustained damage than it does in that area. Hence why I pair it with Grenado or some of the other builds pair it with Shadow Strike/Phantasmal Blades - to try and cover that weakness some more.
Some points I want to make on my Purifier as well as you’ve brought it up:
Even so, Gandarr provides more of it. 30% compared to 19% is massive. When you also consider that % damage reduction reduces the offensive debuffs your character receives, it becomes even more powerful to have a bigger source of it.
In my guide I mention the following:
Damage taken observed by health jumps before and after you start spamming Gandarr on that Purifier in my experience is a day and night level of difference.
I’d honestly say Gandarr is more important than Grenado on that Purifier to the point that it’s the primary skill. If anything, it would not work without Gandarr. Losing it means you lose one of your main sources of ADCtH, you lose a good 200 DA shred, the previously mentioned damage reduction gets cut by a 1/3 going from 30%->19% and you lose a valuable bind for Attak’Seru, one of the most powerful T3s if you can fully convert and proc it consistently - which that build can do.
While Grenado is nice for the additional burst every few seconds and especially on Ulzuin’s Chosen chains, the impact from losing it is lower if you were to remove or replace it than if you were to remove or replace Gandarr instead.