With a grade of 7, it is in Near Mint (NM) condition, a testament to its well-preserved state
Then there is Dreadhorde Invasion and Bitterblossom
Its a toolkit set (modular, slightly odd, and full of potential if you know how to build with it)
That argumentation applies even more to Legacy than Modern since you clearly see Expressive Iteration being extraordinary in Delver, good in Control and non-existing in absurdly strong combo decks like Storm, Doomsday or Sneak & Show
The spell in question is from a specific spellbook, and each one also allows you to spend mana as though it were of any color to cast it
Anywhere Crucible sees play, this has a pretty good chance of seeing play instead for that reason