Hell difficulty used to feel like a hard "nope" for a fire-focused Druid, mostly because every other pack laughed at your damage. Terror Zones and Sunder charms flipped that script, though, and I wanted proof that didn't depend on a billionaire stash tab. So I ran the Ancients on Players 8 with a deliberately plain setup and just enough trading to stay sane, including the odd diablo 2 resurrected runes pickup when my drops refused to cooperate.
No Enigma. No Infinity. No "teleport everywhere and pretend positioning doesn't matter." The core was simple: Ravenlore with a solid fire facet, a Flame Rift charm to crack immunes, and an amulet with teleport charges for those moments when walking is basically a death wish. My merc wore Flickering Flame so my own fire res didn't get nuked by the Sunder penalty, and so I could lean harder into -enemy fire res without feeling like paper. It's not a poverty build, but it's also not ten high runes stitched together pretending to be a guide.
If you've ever felt like your Fissure and Volcano "should" be deleting bosses but somehow aren't, you'll spot it fast: Next Hit Delay. Stack the skills on the exact same spot and a bunch of hits just don't register the way you think they do. You can't brute-force it by mashing faster. You space them. You stagger them. You let the game breathe for a second. Once you start casting with intent, the build stops feeling random and starts feeling like you're actually driving it.
On P8, the Summit is where sloppy casting gets punished. I handled them in a clean order. First was Talic, because Whirlwind plus chaos is a mess. I'd drop Fissure under myself and just bait him through it; moving targets take the full pain, and he burns down way quicker than you'd expect. Next was Madawc. He loves to stand there and throw, so Volcano right on his feet is perfect: the eruption ticks connect over and over, and the physical portion helps too. Korlic was last, mostly a patience check. Keep space, recast smart, don't overlap everything, and use teleport charges only to reset a bad angle instead of trying to play Sorc.
Sunder gets you access, not damage. Dropping an immune monster to 95% fire res still means your big numbers turn into a warm breeze unless you stack -res from gear. That's why Ravenlore and Flickering Flame feel so different from "generic +skills." If you're missing pieces, you can grind forever, or you can shortcut the boring part by grabbing what you need through U4GM and spend your time actually learning the rhythm of the build instead of living in Lower Kurast.
