bastion deck yugioh Bastion's Dueling Challenge in Yu-Gi-Oh! GX Bastion Misawa - Yugipedia

You are only allowed to have 5 monsters on the field at a time, and once you play a monster in a spot you CANNOT change its location except by card effect

The timing restriction seems to turn people off, but you can get absolutely incredulous amounts of value off this spell, at instant speed, during someone elses turn

Relinquished is eligible for Trading Card Game tournaments, having Common rarity but defeating opponents most of the time during duels

Since they operate as a bulk buyer rather than a peer-to-peer marketplace, they eliminate the need for individual listings, customer service, and setting hundreds of individual prices