Darksteel Mutation

Darksteel Mutation causes the enchanted creature to lose all abilities except indestructible at the time it becomes enchanted. Any abilities the creature gains after that point will work normally.

The creature will keep any supertypes it previously had. Notably, if Darksteel Mutation is enchanting a legendary creature, that creature will continue to be legendary. Also, if it's enchanting a commander, that creature will continue to be a commander.

In some rare cases, the creature may have subtypes other than creature types before becoming enchanted with Darksteel Mutation. If it had any other artifact subtypes (such as Equipment), it will retain those. If it had any subtypes other than artifact types and creature types (such as Shrine), it won't retain those.

Darksteel Mutation overwrites any previous effects that set the enchanted creature's power or toughness to a specific value. Any such effects that start to apply after Darksteel Mutation entered the battlefield will work normally.