Blood Moon

If a nonbasic land has an ability that triggers "when" it enters the battlefield, it will lose that ability before it can trigger.

Wotc — August 07, 2020

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 the first ability of Cavern of Souls.

Wotc — August 07, 2020

Nonbasic lands will lose any other land types and abilities they had. They will gain the land type Mountain and gain the ability "{T}: Add {R}."

Wotc — August 07, 2020

This effect 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."

Wotc — August 07, 2020