Why not just "exile target artifact or enchantment"?

Thats not what it does :D

Lifespring Blast, flavor wise, is a steady stream of energy, it erodes artifacts and enchantments, destroying them, however indestructible ones can't be damaged, so eventually as the spring flows over those, they accumulate energy and eventually self-evaporate and are drawn into the void.

Use the "choose one" format(?)

Choose one -

• Destroy target artifact.

• Destroy target enchantment.

• Exile target permanent with indestructible.

OR better yet:

"Exile target artifact, enchantment, or permanent with indestructible."

That last line works best I think. But that's a bit cheap at 3cc for exiling artifacts and enchantments, I'll use the bullet point format for now.

­Act of Authority exiles an artifact-or-enchantment for 1MM, and then gets to optionally do it again later. But yes, this is fine.