Season 15 has turned Resplendent Sparks into one of the most sought-after materials in the game, since they are the gateway to crafted Mythic Uniques and by extension a full Mythic loadout. With Hell difficulty capstone dungeons, Uber Tristram, and the triple Prime Evil fight all rewarding players who show up geared to the teeth, stacking Sparks fast is the difference between watching the endgame and playing it. This guide covers every worthwhile Resplendent Spark farm in Season 15, including the fastest boss runs, the Butcher AFK loop that is pulling up to 40 Mythics per hour, and the crafting tricks that turn a pile of salvaged Mythics into the exact item you want.
Diablo 4 Season 15 Resplendent Spark Farm Guide
Resplendent Sparks are the primary crafting currency behind Mythic Uniques this season, with the Horadric Cube's Upgrade to Mythic recipe costing five Sparks per item. The catch is that any item crafted this way gets a "crafted" tag, and only one crafted Mythic Unique can be equipped at a time. The community workaround is to craft three of the same Mythic, then feed them into the 3:1 unique recycle craft to produce a fresh untagged Mythic. That means Spark income is the single biggest bottleneck to running a full Mythic loadout, and the drop rate is generous enough this season that dedicated farmers can pull enough Sparks in a single evening to build one full item. With that context in place, let's go through where these Sparks actually come from and how to farm them at scale.
Where and How To Farm Resplendent Sparks?
1. Hell Difficulty Capstone Dungeons (Best Consistent Farm)
The most reliable Spark farm in Season 15 is running the three Hell difficulty seasonal capstone dungeons on loop. Each one has no key requirement, and the final Prime Evil boss at the end of every run carries an unusually high Mythic Unique drop rate along with a random chance to drop three Resplendent Sparks outright on death.
Fastest option: World Stone Keep is the quickest of the three dungeons to clear, which is why most farmers run it in a loop. However, all three are worth rotating through because each one is tied to a different Prime Evil Splinter, and you need one of each to progress toward Uber Tristram.
Mythic salvage math: Salvaging 15 Mythic Unique drops gives you enough Sparks for one Mythic craft of your choosing. Since every 10 to 15 Primevals dropped a pile of around eight legendaries with a minimum of two greater affixes each, plus additional Mythic rolls, you can build up Spark income surprisingly fast even from items you never wanted to keep.
Bonus drops from these bosses include:
Mythic Seals, one of the top sources this season
Prime Evil Splinters, one attached to each of the three Hell dungeons
Random Legendaries with greater affixes
Occasional direct Resplendent Spark drops
2. Uber Tristram Triple Prime Evil Fight
Combining your three Prime Evil Splinters in the Horadric Cube produces a Wirt's Lucky Coin, which acts as the entry ticket to the triple Prime Evil encounter in Old Tristram. Interact with the well in the zone to open a portal to the fight.
This interaction had been bugged since the start of the season with roughly a 50/50 chance of eating your coins for nothing, but a recent patch fixed the issue. Feel free to spam your coins into the well now, portals will spawn reliably and rewards land properly.
The fight itself puts three Prime Evils on the field at once and drops a heavy stack of Mythic Uniques, including a special Mythic charm that can only be obtained here. Reports from post-patch runs mention getting four Mythic charms in a single kill, plus stacks of general Mythic items. If you were sitting on Wirt's Lucky Coins waiting for the bug to be fixed, now is the time to burn them.
3. The Butcher AFK Farm on Warlock
A newer strategy has surfaced that pulls up to 40 Mythic Uniques per hour, with some players reporting 18 Mythics in a two-hour session. It works best on Warlock, and the whole setup is designed around chain-spawning The Butcher inside a Nightmare Dungeon so his Beast in the Ice loot table drops Mythics.
What you need before starting:
A strong character, ideally Warlock, to survive stacking elite monster power
Mephisto Prime Evil power equipped
Three War Plan points spent on the Horadric Hunter node in the Nightmare Dungeon tree
The Mist Brother, Dread Revival, and Out of Cold nodes selected
A Splinter of Damnation if your damage can keep up, or a Splinter of the Black Stone for the AFK version
Nemesis affix on the Nightmare Sigil for extra elite spawns
Why this works: Mist Brother allows The Butcher to spawn inside Nightmare Dungeons, and it synergizes with Dread Revival so you can end up with up to four Butchers per spawn. Out of Cold is the sneaky piece of the puzzle since it swaps The Butcher's loot pool over to Beast in the Ice, which is why he starts dropping Mythic Uniques and stacks of Ring of the Eightfold like a Beast in the Ice chest would.
The AFK version: With the Splinter of the Black Stone equipped on a Warlock, killing your own minions counts as kills for the splinter, and it also counts toward spawning The Butcher. That means you can go into demon form, spam Blazing Scream and Bombard while stacking Bombardment charges, and your own minion deaths trigger endless Butcher spawns while you literally hold down a button. Ring of Wigo speeds this up further thanks to attack speed if you have one available.
The active version: If you would rather not AFK, pre-farm around 20 elites outside the dungeon so your Horadric Hunter counter is close to popping when you enter. Once inside, kill elites to spawn Horadric Altars, then click the altars rapidly using a mouse scroll wheel bound to "interact" for faster clicks. Do this only after grabbing a shrine, since the shrine will store all the elites you kill and re-release them when the timer ends, doubling your monster count.
4. World Boss Special Chests and Rank Boxes
World Boss special chests, the ones that only occasionally drop after killing a world boss, can roll greater affix legendaries and have a chance at Mythic drops. Higher tier Season Rank boxes also drop good multi-greater affix items and Mythic rolls if you have not opened them yet this season. These are not repeatable farms, but they are free income you should not skip.
5. Lair Bosses via Helltide Keys
Helltide runs drop Lair Boss keys as part of the general reward pool. Lair bosses each have their own Mythic Unique tied to their loot table, which is important because Season 15 uses the rule that a Mythic drops from the same source as its non-Mythic equivalent. If you want a specific Mythic, target-farming the boss that drops the base unique is the theoretical fastest route, though in practice the crafting workaround via Sparks tends to be more reliable.
Turning Sparks Into a Full Mythic Loadout
The trick to running more than one Mythic Unique at the same time is the crafted tag. Straight up crafting a Mythic at the Horadric Cube slaps the crafted tag on it, and only one crafted Mythic can be equipped per character. Here is the workaround:
Farm enough Sparks to craft three copies of the same Mythic Unique (15 Sparks total)
All three will have the crafted tag individually and cannot be equipped together
Use the 3:1 unique item recycle craft in the Horadric Cube to combine them into one new Mythic
The recycled Mythic has random affixes but does NOT carry the crafted tag
Equip freely alongside your other crafted Mythic
Repeat this cycle for each Mythic slot in your loadout, and you can eventually run a fully Mythic character without ever hitting the one-crafted-item cap.
Supporting Materials Worth Farming Alongside Sparks
While you are running these Spark farms, a few other materials matter for finishing off Mythic gear rolls.
Cool Tuning Prisms: After the recent patch, the Ingenuity Tribute in Kurast Undercity properly drops Cool Tuning Prisms from the material bargain. Runs post-patch have produced 13 prisms in a single tribute, with some players reporting even higher counts. Use these to roll the bonus legendary aspect on your amulet.
Set Bonus Charms and Legendary Seals: The Tribute of the Horadrim in Kurast Undercity is the top source for these. If you still need a legendary seal with six slots, this is where to hunt it down.
Echoing Hatred Charms and Seals: The Goblin Plunder Bags at the end of Echoing Hatred drop loads of charms and seals, which is ideal for filling out talisman slots to pair with your Mythic gear.
Value Reroll Craft: The new Horadric Cube option that rerolls affix values without changing which affixes are on the item is safe to use on greater affix gear since it will not reroll GAs themselves. Use it to squeeze the top possible values out of your rolled Mythics after crafting them.
If your priority is a clean, low-effort Spark farm, put World Stone Keep on repeat and salvage every Mythic that drops. If you want the maximum Mythic per hour count in the game right now, run the Warlock Butcher setup with Mist Brother, Dread Revival, and Out of Cold slotted, and use the Splinter of the Black Stone to AFK farm on minion deaths. When you have banked enough Prime Evil Splinters, combine them into Wirt's Lucky Coins and cash in on Uber Tristram for the exclusive Mythic charm and stacks of extra Mythic drops. Combine those routes across a single play session and Season 15's Spark economy tilts hard in your favor, letting you push toward a full Mythic loadout faster than any previous season.