Thats because auctions limit the amount of time you can get eyes on your listing while also filtering out buyers who dont immediately have the capital on hand (but who would otherwise be interested in buying at a later time)
Even as a 4-mana colorless instant, this modal spell gets tons of work done for an Eldrazi player
For example, suppose [c]Shadowmage Infiltrator[/c], a 1/3 creature with fear, attacks me, the defending player
Kaito Shizuki While Kaito Shizuki isn't a dedicated phasing card, it does phase out the first turn it enters the battlefield
Outside of affinity, these are just great with cards that want you to have tons of artifacts, like Emry, Lurker of the Loch, Cyberdrive Awakener, or Urza's Saga
The card depicting the leader of the Admirals features striking alternate art unavailable in any other iteration