Windshaper Planetar — ruling 1

You may cast Windshaper Planetar outside of a declare attackers step. If Windshaper Planetar enters the battlefield outside of a declare attackers step, its ability simply doesn't trigger.

Windshaper Planetar — ruling 2

Reselecting which player or planeswalker a creature is attacking ignores all requirements, restrictions, and costs associated with attacking.

Windshaper Planetar — ruling 3

Reselecting which player or planeswalker a creature is attacking doesn't cause “whenever this creature attacks” abilities to trigger.

Windshaper Planetar — ruling 4

If you reselect which player or planeswalker an attacking creature is attacking, that creature is still considered to have attacked the player or planeswalker as declared, but it is now attacking the new player or planeswalker.

Windshaper Planetar — ruling 5

If an ability targets something controlled by the “defending player” of an attacking creature and the defending player for that creature changes before that ability resolves, the ability won't resolve because its target has become illegal.

Windshaper Planetar : règles, fonctionnement et interactions (MTG)

Windshaper Planetar 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

Flash Flying When this creature enters during the declare attackers step, for each attacking creature, you may reselect which player or permanent that creature is attacking. (It can't attack its controller or their permanents.)

How it works : Windshaper Planetar

Original English text — Wizards of the Coast / Scryfall

#1June 10, 2022· Wizards of the Coast
You may cast Windshaper Planetar outside of a declare attackers step. If Windshaper Planetar enters the battlefield outside of a declare attackers step, its ability simply doesn't trigger.
No other card is named in this ruling.
#2June 10, 2022· Wizards of the Coast
Reselecting which player or planeswalker a creature is attacking ignores all requirements, restrictions, and costs associated with attacking.
No other card is named in this ruling.
#3June 10, 2022· Wizards of the Coast
Reselecting which player or planeswalker a creature is attacking doesn't cause “whenever this creature attacks” abilities to trigger.
No other card is named in this ruling.
#4June 10, 2022· Wizards of the Coast
If you reselect which player or planeswalker an attacking creature is attacking, that creature is still considered to have attacked the player or planeswalker as declared, but it is now attacking the new player or planeswalker.
No other card is named in this ruling.
#5June 10, 2022· Wizards of the Coast
If an ability targets something controlled by the “defending player” of an attacking creature and the defending player for that creature changes before that ability resolves, the ability won't resolve because its target has become illegal.
No other card is named in this ruling.