Use A Vaal Orb On A Unique Jewel And Convert It Into Another Unique (Vaal) Jewel.
I'd Get A Few Uniques (You Arent Going To Use) In Your Stash Before Trying This One.
Each Of The Following Have About A 1/4th Chance Of Happening When You Use A Vaal Orb On A Jewel:
(Taken From The Wiki)
- Adds a random implicit modifier
- Transforms the jewel into a random unique vaal jewel
- Reroll the item with random modifiers
- Nothing happens (Still Adds Corrupted Modifier)
Achievement Pops As Soon As You Roll The Unique Jewel.
It Took Me 6 Tries To Get One, But It Could Take You 16 Or So in A Terrible RNG World.
Good Luck!