I finally managed to get together everything that I needed to play a Hellcat-buffed Cluster Bombs Marauder, but when I stepped into a Greater Rift to see how much of a power boost I got from completing the build I had worked so hard for it was pretty disappointing. I'd been using Maelstrom up to this point, and it took a few failed runs for me to realize that the play style needed for Cluster Bombs is completely different.
At first, as I started pushing above GR 65, I kept dying; little stupid enemies that I couldn't see among the chaos would one-shot me with physical damage (bypassing the protection of my Esoteric Alteration). I felt I had no choice but to get tankier, so I switched my Cube jewelry affix from Convention of Elements to the Ring of Royal Grandeur so that I could equip an Ancient Cloak of Garwulf that I lucked into (and still keep Hellcat in the Cube's armor slot). It definitely helped me to stay alive through GR 68 and 69, but then I got stuck for a while on GR 70. It got really frustrating. With Marauder, if you get killed it stops you cold and you need to retreat, set up sentries again for the multiplier (waiting for two charges), and often wait for the Vengeance that you lost upon death to cool down as well.
After a couple of runs that pissed me off enough to quit the game session instead of bothering to finish the rifts, I started to figure out Cluster Bombs a bit. You can't just plant yourself 50 yards away from the enemy and fire volleys toward them like with Maelstrom because the time-to-kill is much slower. The major damage comes after a delay, so standing still leaves you vulnerable, especially to rushing physical-attack enemies, no matter how many meat shields you've got fighting for you in between. Instead, you want to cover an area with your grenades little by little, which is part of why players round up enemies and bait them into gathering together. (Incidentally, I really wish I had given that Ess of Jordan to my Templar way back when instead of Cubing it.) So, to keep out of trouble, I adopted a tactic of moving a bit after every shot, circling around my target as best I could. It worked well enough; after repeatedly failing GR 70 I managed to beat it with around 2 minutes 15 seconds left on the clock.
But I'm left with two problems. First, I'm not sure how to get stronger from here. Yes, I'd love to get better rolls on my ring set. There's a potential 30% more crit damage on my amulet. And obviously I can work on upgrading my legendary gems; maybe Bane of the Stricken will start to become really useful from this point on. Does anything else jump out as an improvement I can make?
But the more important problem is that I'm not sure I like this new play style! It clearly has a high skill ceiling and requires the player to be more active, and, honestly, even after succeeding with it I find it a bit exhausting. Plus, there's an indirect quality to your attacks that's just unsatisfying. This is the build that I've been working towards this whole time, but, ironically, I kind of want to go back to rockets! I happen to have the same Hellfire Amulet but with a Physical bonus instead of Fire. If I reroll my Wraps of Clarity to match and run Shooting Stars, forfeiting the Hellcat Waistguard bonus, am I going to be sacrificing a lot of damage potential? I was thinking that I might try to forego Esoteric Alteration and plug Zei's Stone of Vengeance back in since I'll be able to use Visage of Gunes in the Cube again as well as fight from a distance more, so maybe that will help. I don't think I'll miss the healing from Maelstrom; I doubt it can help much with the incoming damage of high GRs.
What do you think? Where should I go from here? I'm pretty confident that I can complete Conqueror in the Season Journey before time runs out with the build I'm using now (aside from a big change-up just for Boss Mode), although Guardian is probably off-limits with its requirement for three Conquests (and I can live with that). But it would be nice to have a plan for my character's progress while I'm grinding away at gem upgrades, and of course becoming stronger would certainly help with faster T13 rift clears and Boss Mode. Besides, this is much farther than I've ever pushed in Diablo before, and I'd like to keep moving forward in the off-season. While that definitely means trying other sets and builds, I want to continue with this one, as well.
I hope this kind of post isn't too obnoxious. I figure some people like to tinker with other people's characters vicariously, and anyway I wanted to share where my head's at with Cluster Bombs. Thanks for reading!
Played around with this a lot the last couple of days changing anything and everything trying to get more dps. Frankly, what you have is sort of the dps limit of this set until the new patch goes live.
Frankly if you want to push higher i would switch to the shadow set which will instantly quadruple your dps. Sorry i couldn't be more of help.