The "Textless Cosmic Foil" variant of The Mind Stone from the Marvel Super Heroes set has an estimated pull rate of less than 1% in Collector Boosters
Congregation at Dawn is a non-convoke backup to Chord of Calling, lessening the need for raw card draw like Harmonize
Whenever you cast a spell that targets one or more of your Creatures, the +1/+1 counter is placed on Arcee, Acrobatic Coupe, which is great, but she immediately Converts back to the Robot half that no longer receives +1/+1 counters
It does have at least one other, very different way to use the card: You can target yourself with Lost Legacy
Tapping a land and a creature for a single mana is quite bad, but lands like this have a home in decks that actively want to tap their own creatures
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.) Enchantment - Aura Color tag templates(None) Imprisoned in the Moon Enchant creature, land, or planeswalker Enchanted permanent is a colorless land with " : Add " and loses all other card types and abilities