Myr Custodian — ruling 1

As the enters-the battlefield ability resolves, first you scry 2. Then each opponent in turn order chooses whether or not to scry 1. Those who do (likely all of them) look at the top card of their library at the same time, then they decide in turn order where their card goes. Each opponent will know the choices of previous players in turn order before making their own choices.

Myr Custodian : règles, fonctionnement et interactions (MTG)

Myr Custodian 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

When this creature enters, scry 2. Then each opponent may scry 1. (To scry X, a player looks at the top X cards of their library, then puts any number of them on the bottom and the rest on top in any order.)

How it works : Myr Custodian

Original English text — Wizards of the Coast / Scryfall

#1February 4, 2023· Wizards of the Coast
As the enters-the battlefield ability resolves, first you scry 2. Then each opponent in turn order chooses whether or not to scry 1. Those who do (likely all of them) look at the top card of their library at the same time, then they decide in turn order where their card goes. Each opponent will know the choices of previous players in turn order before making their own choices.
No other card is named in this ruling.