Because it is on that exclusive list of metal cards from Pokemon, it will likely hold a special place in the hearts of collectors
Since the terastalization phenomenon is a fairly recent and quite popular game mechanic in the mainline series, a Pokmon TCG video game sequel could include various ex and stellar Pokmon cards to add an extra challenge in combat
Its exhaust ability is the ultimate finisher, dumping your entire hand onto the field at once
Court of Grace Court of Grace is a little like Palace Jailer on a stick, but it generates fliers instead of exiling a creature
Thats just gravy
I don't believe it saw much, if any, Constructed play at the time (I may be wrong on this, but can't seem to find anything from researching online), but the card was considered quite powerful stat-wise and featured some keywords not commonly found on Green cards