Auspicious Starrix — ruling 1

If an Aura is put onto the battlefield without being cast, the Aura’s controller-to-be chooses what it will enchant as it enters the battlefield. An Aura put onto the battlefield this way doesn’t target anything (so it could be attached to an opponent’s permanent with hexproof, for example), but the Aura’s enchant ability restricts what it can be attached to. If the Aura can’t legally be attached to anything, it remains in its current zone.

Auspicious Starrix — ruling 2

An Aura being put onto the battlefield this way can’t enchant anything else that is being put onto the battlefield at the same time.

Auspicious Starrix — ruling 3

Auspicious Starrix’s effect doesn’t count as playing lands. It can put land cards onto the battlefield even if it’s not your turn or if you’ve already played your land for the turn.

Auspicious Starrix — ruling 4

If there are fewer than X permanent cards in your library, you exile your entire library and put the permanent cards in it onto the battlefield.

Auspicious Starrix — ruling 5

Any cards that you exile but don’t put on the battlefield for any reason (for example, because the card is an instant card or an Aura that can’t enchant anything) remain in exile.

Auspicious Starrix : règles, fonctionnement et interactions (MTG)

Auspicious Starrix 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

Mutate (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.) Whenever this creature mutates, exile cards from the top of your library until you exile X permanent cards, where X is the number of times this creature has mutated. Put those permanent cards onto the battlefield.

How it works : Auspicious Starrix

Original English text — Wizards of the Coast / Scryfall

#1April 17, 2020· Wizards of the Coast
If an Aura is put onto the battlefield without being cast, the Aura’s controller-to-be chooses what it will enchant as it enters the battlefield. An Aura put onto the battlefield this way doesn’t target anything (so it could be attached to an opponent’s permanent with hexproof, for example), but the Aura’s enchant ability restricts what it can be attached to. If the Aura can’t legally be attached to anything, it remains in its current zone.
No other card is named in this ruling.
#2April 17, 2020· Wizards of the Coast
An Aura being put onto the battlefield this way can’t enchant anything else that is being put onto the battlefield at the same time.
No other card is named in this ruling.
#3April 17, 2020· Wizards of the Coast
Auspicious Starrix’s effect doesn’t count as playing lands. It can put land cards onto the battlefield even if it’s not your turn or if you’ve already played your land for the turn.
No other card is named in this ruling.
#4April 17, 2020· Wizards of the Coast
If there are fewer than X permanent cards in your library, you exile your entire library and put the permanent cards in it onto the battlefield.
No other card is named in this ruling.
#5April 17, 2020· Wizards of the Coast
Any cards that you exile but don’t put on the battlefield for any reason (for example, because the card is an instant card or an Aura that can’t enchant anything) remain in exile.
No other card is named in this ruling.