Letting a player fusion summon a Gem-Knight using cards from their deck is good in its own right, and the target people often go for is Gem-Knight Seraphinite
I liken it to Hangar Scrounger, which many people realized could go infinite with Seeker of Skybreak and insisted that it could be a thing
It doesnt copy whether that creature is tapped or untapped, whether it has any counters on it or Auras and/or Equipment attached to it, or any non-copy effects that changed its power, toughness, types, color, and so on
Notably, many participants use it for propaganda, such as Yuya advocating against the City's slavery-based system, Shinji Weber using it to rally the Commons for the revolution, Roget's failed attempt to crush public resistance by using Sergei as a stand-in, Yuzu and later Sora's hijacking of the same broadcasting system to communicate with their allies, and most importantly, Yuya and Jack's finals duel to unite the City
1 Trainer card made waves after selling for about $75,000 at a Heritage Auctions event, instantly ranking it among the most prized Pokemon TCG trophy cards ever
The deck contains ten double-faced tokens, with the Spirit tokens and Angel tokens receiving new art by Scott M