It may be a tough play in Limited formats because of its mana cost and likely wont change much in Constructed since its a reprint
Or did you have a different idea
Not all the Pokdexes were instantly available, meaning fans actually anticipated updates to the game when they occurred, attempting to add more Pokmon to their collection
In all seriousness though, it really isnt removal, but rather a fun way to maximize the value that certain creatures give you
This means that if Glimpse, the Unthinkable isn't on the battlefield, players are free to choose its name with Meddling Mage or choose Glimpse, the Unthinkable in a player's hand with Thoughtseize
More cards for themes introduced in Genesis Impact , Ancient Guardians , Lightning Overdrive , Dawn of Majesty , Ghosts From the Past , and more