The Phasing of Zhalfir — ruling 1

Permanents that phase out as The Phasing of Zhalfir's first and second chapter abilities resolve don't phase in during their controllers' untap steps while the Saga is on the battlefield. After it leaves the battlefield, they will phase in during their controller's next untap step as normal.

The Phasing of Zhalfir — ruling 2

Phased-out permanents are treated as though they don't exist. They can't be the targets of spells or abilities, their static abilities have no effect on the game, their triggered abilities can't trigger, they can't attack or block, and so on.

The Phasing of Zhalfir — ruling 3

As a permanent is phased out, Auras and Equipment attached to it also phase out at the same time. Those Auras and Equipment will phase in at the same time that permanent does, and they'll phase in still attached to it.

The Phasing of Zhalfir — ruling 4

Normally, permanents phase back in during their controller's untap step, immediately before that player untaps their permanents. Creatures that phase in this way are able to attack and pay a cost of {T} during that turn. If a permanent had counters on it when it phased out, it will have those counters when it phases back in.

The Phasing of Zhalfir — ruling 5

An attacking or blocking creature that phases out is removed from combat.

The Phasing of Zhalfir — ruling 6

Phasing out doesn't cause any "leaves the battlefield" abilities to trigger. Similarly, phasing in won't cause any "enters the battlefield" abilities to trigger.

The Phasing of Zhalfir — ruling 7

Any continuous effects with a "for as long as" duration, such as that of Extraction Specialist, ignore phased-out objects. If ignoring those objects causes the effect's conditions to no longer be met, the duration will expire.

The Phasing of Zhalfir — ruling 8

Choices made for permanents as they entered the battlefield are remembered when they phase in.

The Phasing of Zhalfir : règles, fonctionnement et interactions (MTG)

The Phasing of Zhalfir 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

Read ahead (Choose a chapter and start with that many lore counters. Add one after your draw step. Skipped chapters don't trigger. Sacrifice after III.) I, II — Another target nonland permanent phases out. It can't phase in for as long as you control this Saga. III — Destroy all creatures. For each creature destroyed this way, its controller creates a 2/2 black Phyrexian creature token.

How it works : The Phasing of Zhalfir

Original English text — Wizards of the Coast / Scryfall

#1September 9, 2022· Wizards of the Coast
Permanents that phase out as The Phasing of Zhalfir's first and second chapter abilities resolve don't phase in during their controllers' untap steps while the Saga is on the battlefield. After it leaves the battlefield, they will phase in during their controller's next untap step as normal.
No other card is named in this ruling.
#2September 9, 2022· Wizards of the Coast
Phased-out permanents are treated as though they don't exist. They can't be the targets of spells or abilities, their static abilities have no effect on the game, their triggered abilities can't trigger, they can't attack or block, and so on.
No other card is named in this ruling.
#3September 9, 2022· Wizards of the Coast
As a permanent is phased out, Auras and Equipment attached to it also phase out at the same time. Those Auras and Equipment will phase in at the same time that permanent does, and they'll phase in still attached to it.
No other card is named in this ruling.
#4September 9, 2022· Wizards of the Coast
Normally, permanents phase back in during their controller's untap step, immediately before that player untaps their permanents. Creatures that phase in this way are able to attack and pay a cost of during that turn. If a permanent had counters on it when it phased out, it will have those counters when it phases back in.
No other card is named in this ruling.
#5September 9, 2022· Wizards of the Coast
An attacking or blocking creature that phases out is removed from combat.
No other card is named in this ruling.
#6September 9, 2022· Wizards of the Coast
Phasing out doesn't cause any "leaves the battlefield" abilities to trigger. Similarly, phasing in won't cause any "enters the battlefield" abilities to trigger.
No other card is named in this ruling.
#7September 9, 2022· Wizards of the Coast
Any continuous effects with a "for as long as" duration, such as that of Extraction Specialist, ignore phased-out objects. If ignoring those objects causes the effect's conditions to no longer be met, the duration will expire.
No other card is named in this ruling.
#8September 9, 2022· Wizards of the Coast
Choices made for permanents as they entered the battlefield are remembered when they phase in.
No other card is named in this ruling.
#9September 9, 2022· Wizards of the Coast
As a Saga with read ahead enters the battlefield, its controller chooses a number from one to that Saga's greatest chapter number. The Saga enters the battlefield with the chosen number of lore counters. Neither choosing the number nor putting the counters on the Saga use the stack, and neither can be responded to.
No other card is named in this ruling.