It can also attack multiple times per turn, putting its stats to good use and ending games quickly
PSA 10 copies have sold between $300,000-420,000 at major auction houses (Heritage, PWCC)
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
If you have "Endless Engine Argyro System" in your GY at activation, you can activate both effects (at resolution, negate, then banish)
From the manga to the anime to the card game, there have been crowds of people over the past two decades who have been drawn to it
This rule keeps the game varied and prevents players from stacking too many identical power cards