Zaffai, Thunder Conductor

• WOTC Official Reminder Textofficial rules
  Scry — Look at the top N cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.

• WWizards of the Coast2021-04-16
  Official Ruling
  "That spell's mana value" refers to the spell that caused the ability to trigger, not the card you look at when you scry.
• WWizards of the Coast2021-04-16
  Official Ruling
  If an effect creates a copy of an instant or sorcery spell, this will also cause the magecraft ability to trigger.
• WWizards of the Coast2021-04-16
  Official Ruling
  For example, if you control Archmage Emeritus and cast an instant or sorcery spell, Archmage Emeritus's magecraft ability will trigger and you will draw a card.
• WWizards of the Coast2021-04-16
  Official Ruling
  If the instant or sorcery spell has in its mana cost, X is the value chosen for X as the spell was cast.
• WWizards of the Coast2021-04-16
  Official Ruling
  Some effects instruct you to copy an instant or sorcery card in a zone other than the stack. These copies do not cause magecraft abilities to trigger. However, most effects that do this also allow you to cast the copy, and casting the copy will cause magecraft abilities to trigger.
• WWizards of the Coast2021-04-16
  Official Ruling
  If an effect creates multiple copies of an instant or sorcery spell, magecraft abilities trigger once for each copy created by the effect.
• WWizards of the Coast2021-04-16
  Official Ruling
  Each magecraft ability has a different effect, although they all have the same trigger condition, whenever you cast or copy an instant or sorcery spell.
• WWizards of the Coast2021-04-16
  Official Ruling
  The wrong card name was inadvertently included in Zaffai's printed rules text. The text above is correct and the full name of the card is Zaffai, Thunder Conductor.

Rulings via Scryfall