I have the 4-piece bonus of the Marauder's Set, but not the 6-piece yet. I also have the Spines of Seething Hatred, which means that my Chakram generates hatred, rather than spending it.
I'm having trouble understanding the 4-piece bonus,
Sentries cast your Hatred spender when you do.
It seems to work fine with Multi-shot, so I assume I'm not confusing the meanings of 'spender' and 'generator'; I use Multi-shot and three more spray out from my sentries. But Rapid Fire, with the Bombardment rune, doesn't appear to work (ie. I don't see my sentries dropping a stream of grenades, or even any grenades), whereas it does work with Chakram (I use it with Twin Chakram, and my sentries cover the screen with them). I thought this was pretty weird, because the 6-piece bonus specifically declares Chakram as one of my generators.
So, (a) does this just mean the Chakram is covered by both set bonuses (ie. it's a spender and generator of hatred), and (b) does the 4-piece bonus work with Rapid Fire, and if so, why can't I see it working?
EDIT: This question argues that Chakram would be considered a spender but not a generator. But as far as I can see, I seem to be able to have my cake and eat it too, if the 6-piece bonus text and my experience are both accurate:
Your generators, Elemental Arrow, Chakram, Impale, Multishot, and
Cluster Arrow deal 100% increased damage for every active sentry.
I'll also keep this question open because I'm still confused about how Rapid Fire works with this.
Best Answer
Rapid Fire is a channelled ability, that is, you're continually paying Hatred to keep it active. Sentry Turrets will not use any channelled abilities, only ones with the full Hatred cost paid up front in full. Certain other Hatred spenders (such as Sentry Turret itself - imagine how broken that would be!) are also excluded for various reasons.
Also, even with the Spines of Seething Hatred equipped, Chakram does still count as a Hatred spender. The same is true of Elemental Arrow with Kridershot equipped.