If you find a copy of this Ultra Rare card youll have yourself a nice chunk of change, as it goes for almost three times as much as the Super Rare
The Enigma Jewel / Locus of Enlightenment The Enigma Jewel is an activated ability build-around for only 1 mana, and its very easy to put into your decks and play
Besides the obvious free creature sac outlets like Viscera Seer, Tarrian's Soulcleaver also benefits from those Treasure, Clue, and Food tokens you can make and sacrifice at a moments notice
Not surprisingly, the card hasn't been reprinted since 1993 (the very first set of Magic's existence), although there was a Mystery Booster card printed in 2019 called Problematic Volcano which effectively serves as an homage to this card, and according to Ethan Fleischer, a mechanic that worked in a similar vein was experimented with for Theros: Beyond Death in 2020
It answers engines and combo pieces if theyre enchantments, it counters Theros Gods and it counters anything from a board wipe, to a draw spell to a game-winning X-spell