I absolutely love the value tied into the creature and the X-bonus is the cherry on top
Enlightened Tutor (T1, Ext, S , Block) The Mirage set introduced three tutors to the world: Mystical, Worldly, and Enlightened
We've already touched on the fact that card-drawing spells and powerful cards reduce the risk of mana flood (meaning that the deck can afford the risks of playing a high land count)
The spell also has the added benefit of replacing itself by drawing you a card when it is cast as long as you control at least one merfolk, letting it still maintain its usefulness over the course of a game
The ability to cycle this rather than mill it means its not a dead draw
"Draw seven" effects can become truly busted if paired with cards like Narset, Parter of Veils