Galedrifter // Waildrifter — ruling 1

Disturb is found only on the front faces of some double-faced cards.

Galedrifter // Waildrifter — ruling 2

To determine the total cost of a spell, start with the mana cost or alternative cost (such as a disturb cost) you're paying, add any cost increases, then apply any cost reductions. The mana value of a spell cast using disturb is determined by the mana cost on the front face of the card, no matter what the total cost to cast the spell was. (This is a special rule that applies only to nonmodal double faced-cards, including ones with disturb.)

Galedrifter // Waildrifter — ruling 3

When you cast a spell using a card's disturb ability, the card is put onto the stack with its back face up. The resulting spell has all the characteristics of that face.

Galedrifter // Waildrifter — ruling 4

A spell cast this way enters the battlefield with its back face up.

Galedrifter // Waildrifter — ruling 5

"Disturb [cost]" means "You may cast this card transformed from your graveyard by paying [cost] rather than its mana cost."

Galedrifter // Waildrifter — ruling 6

If you copy a permanent spell cast this way (perhaps with a card like Double Major), the copy becomes a token that's a copy of the card's back face, even though it isn't itself a double-faced card.

Galedrifter // Waildrifter — ruling 7

The back face of each card with disturb has an ability that instructs its controller to exile if it would be put into a graveyard from anywhere. This includes going to the graveyard from the stack, so if the spell is countered after you cast it using the disturb ability, it will be put into exile.

Galedrifter // Waildrifter : règles, fonctionnement et interactions (MTG)

Galedrifter // Waildrifter is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Flying Disturb (You may cast this card from your graveyard transformed for its disturb cost.) Flying If Waildrifter would be put into a graveyard from anywhere, exile it instead.

How it works : Galedrifter // Waildrifter

Original English text — Wizards of the Coast / Scryfall

#1September 24, 2021· Wizards of the Coast
Disturb is found only on the front faces of some double-faced cards.
No other card is named in this ruling.
#2September 24, 2021· Wizards of the Coast
To determine the total cost of a spell, start with the mana cost or alternative cost (such as a disturb cost) you're paying, add any cost increases, then apply any cost reductions. The mana value of a spell cast using disturb is determined by the mana cost on the front face of the card, no matter what the total cost to cast the spell was. (This is a special rule that applies only to nonmodal double faced-cards, including ones with disturb.)
No other card is named in this ruling.
#3September 24, 2021· Wizards of the Coast
When you cast a spell using a card's disturb ability, the card is put onto the stack with its back face up. The resulting spell has all the characteristics of that face.
No other card is named in this ruling.
#4September 24, 2021· Wizards of the Coast
A spell cast this way enters the battlefield with its back face up.
No other card is named in this ruling.
#5September 24, 2021· Wizards of the Coast
"Disturb [cost]" means "You may cast this card transformed from your graveyard by paying [cost] rather than its mana cost."
No other card is named in this ruling.
#6September 24, 2021· Wizards of the Coast
If you copy a permanent spell cast this way (perhaps with a card like Double Major), the copy becomes a token that's a copy of the card's back face, even though it isn't itself a double-faced card.
No other card is named in this ruling.
#7September 24, 2021· Wizards of the Coast
The back face of each card with disturb has an ability that instructs its controller to exile if it would be put into a graveyard from anywhere. This includes going to the graveyard from the stack, so if the spell is countered after you cast it using the disturb ability, it will be put into exile.
No other card is named in this ruling.