Zaffai, Thunder Conductor

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.

If an effect creates a copy of an instant or sorcery spell, this will also cause the magecraft ability to trigger.

If the instant or sorcery spell has {X} in its mana cost, X is the value chosen for X as the spell was cast.

"That spell's mana value" refers to the spell that caused the ability to trigger, not the card you look at when you scry.

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.

If an effect creates multiple copies of an instant or sorcery spell, magecraft abilities trigger once for each copy created by the effect.