Magus of the Moon

• WWizards of the Coast2021-03-19
  Official Ruling
  If Magus of the Moon loses its abilities, it continues to turn nonbasic lands into Mountains. This is because effects that change subtypes are applied before considering effects that remove abilities, regardless of the order in which those effects started.
• WWizards of the Coast2021-03-19
  Official Ruling
  Magus of the Moon doesn't affect names or supertypes. It won't turn any land into a basic land or remove the legendary supertype from a legendary land, and the lands won't be named "Mountain."
• WWizards of the Coast2021-03-19
  Official Ruling
  If a nonbasic land has an ability that causes it to enter the battlefield tapped, it will lose that ability before it can apply. The same is also true of any other abilities that modify how a land enters the battlefield or apply "as" a land enters the battlefield, such as that of Vesuva or Cavern of Souls.
• WWizards of the Coast2021-03-19
  Official Ruling
  If a nonbasic land has an ability that triggers "when" it enters the battlefield, it will lose that ability before it can trigger.
• WWizards of the Coast2021-03-19
  Official Ruling
  Nonbasic lands lose any other land types and abilities they had. They gain the land type Mountain and gain the ability ": Add ."

Rulings via Scryfall

• WO
  Wizards of the Coast2026-02-09

  Magus of the Moon was unbanned in historic on February 9, 2026. We believe that Magus of the Moon and Harbinger of the Seas offer the right amount of interactivity against current and future land decks while inflicting minimum damage to the more casual Historic scene. These creatures are generally easier to remove than an enchantment like Blood Moon while being clear and effective options against nonbasic land-centric strategies. Source: https://magic.wizards.com/en/news/announcements/banned-and-restricted-february-9-2026