If you take into consideration double-faced cards, you'll find even higher word counts in rules text
You have to choose a nonland permanent, which means thats on the board somewhere - you cant just name any card in MTGs history like with Pithing Needle or Sorcerous Spyglass, though those dont stop mana abilities, which Scheming Fence does
The singer 3 ability is quite strong, and a similar card (Ariel) had a lot of success in The First Chapter format of Disney Lorcana
Aerie Ouphes Aerie Ouphes is a very elegant design as its own sacrifice outlet
For one, it's the first to name check a specific character, that being the tentacled sea-witch herself, who's been freed from imprisonment and is wreaking her usual havoc upon Lorcana
Since copies are in short supply, that's driven this card's value pretty high