regal merlin
Official Illuvitar burning wallet:
I propose the implementation of a burning wallet (In Illuvium beyond this would be presented as a button). And with this official burn mechanic the illuvitar burned were also removed from the list of Minted.
Example: I have gotten myself 2x copies of the same illuvitar, there are only two of those in existence, i now got the option to make one of those copies unique.
clear knot
FWIW IMX has a burn address you could send assets to already (using transfer). I do think this is a pretty niche thing to do (not many people will want to remove their stuff from existence voluntarily, by my reckoning), but you could burn your Illuvitar if you chose to do so.
I'd actually see including a button as causing more problems than it solves, because people like clicking buttons and almost certainly someone would burn something by accident.
rare sequoia
Also one can just bond a clown nose or something to one of those and that solves uniqueness as well.
lyric jolt
You can use mine 
spice bone