Well, its Darkness type attack, which costs one Darkness Energy and two Colorless, deals 160 damage and makes the Defending Pokmon Confused (check out our guide to Status Conditions in Pokmon for more details)
My mind immediately goes to cards like The Ozolith and Resourceful Defense to start shuffling around counters, not to mention synergy with cards like Elenda, the Dusk Rose and Unruly Mob that grow whenever your creatures die
Packaging cards to ship If your cards turn up bent, as soggy mush, or don't arrive at all, you're going to be hit with complaints and customers asking for their money back
There are lots more examples of toys not being produced and things like that, but I wont dwell on matters of merchandising and anime censorship
There are plenty of Stage 1 decks that rely on ex Pokmon, but these aren't the only Stage 1 Pokmon that are useful, as some single-prize Stage 1 cards are phenomenally powerful in specific strategies
Overall, "Illusion of Chaos" is a phenomenal card that was worthy of its previously high price point