Upgrade Direct Item to Mythic - Horadric Cube recipe - Diablo IV Season 15
The Upgrade Direct Item to Mythic recipe in the Diablo IV Horadric Cube takes 1x Unique item (non-Iconic; 'Crafted'-tag-eligible) + 5x Resplendent Spark and produces Mythic-quality version of the input item.
Inputs
1x Unique item (non-Iconic; 'Crafted'-tag-eligible) - Cannot be Unmodifiable. Item Power requirement DISPUTED: the PTR-era sources consulted for this entry say 850+; one guide's live 2026-09-19 page says 900+. Level 70 / Torment I+ reported by those same PTR-era sources, unverified live.
5x Resplendent Spark - confirmed by 2 independent live sources (one guide, another guide)
Output
Mythic-quality version of the input item - 1:1 deterministic transfer - keeps ALL of the input item's existing affixes, Tempering, and Masterworking exactly as rolled. No RNG on the output.
Restrictions
Cannot be used on an Unmodifiable item
Result carries the 'Crafted' tag; only one Crafted-tag item can be equipped at a time
Iconic Mythics remain obtainable only as Mythic-quality (cannot be produced by this recipe from a Unique version, since Blizzard scrapped PTR plans for Unique versions of Iconic Mythics)
upgradeVisibledisputedNew in Season 15
Blizzard quote: "will be more expensive than the recipes through the Blacksmith or Jeweler, but it will also be a total 1:1 transfer... the random factors are gone. Put in a Tibault's Will with ideal affixes and dialed-in Tempering and Masterworking, and you'll get a Mythic-ized version... with all affixes and modifications retained. The only restriction is that you cannot use this recipe on an Unmodifiable item." Jeweler/Blacksmith-crafted Mythics do NOT carry the Crafted tag, so multiple of those can be equipped simultaneously alongside one Crafted-tag item. Blacksmith also gained a second cache in S15 that rolls only Iconic Mythics at the same cost as the normal Mythic cache.