Space Marine Devastator — ruling 1

You may pay the squad cost any number of times. You will get a token that is a copy of that permanent for each time you paid the squad cost.

Space Marine Devastator — ruling 2

If the spell is countered, the squad ability will not trigger, and no tokens will be created.

Space Marine Devastator — ruling 3

The tokens created by the squad ability aren't "cast," so any abilities that trigger when a spell is cast won't trigger for the copies.

Space Marine Devastator — ruling 4

If, for some reason, the creature doesn't have the squad ability when it's on the battlefield, the ability won't trigger, even if you've paid the squad cost one or more times.

Space Marine Devastator : règles, fonctionnement et interactions (MTG)

Space Marine Devastator 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

Squad (As an additional cost to cast this spell, you may pay any number of times. When this creature enters, create that many tokens that are copies of it.) Grav-cannon — When this creature enters, destroy up to one target artifact or enchantment.

How it works : Space Marine Devastator

Original English text — Wizards of the Coast / Scryfall

#1October 7, 2022· Wizards of the Coast
You may pay the squad cost any number of times. You will get a token that is a copy of that permanent for each time you paid the squad cost.
No other card is named in this ruling.
#2October 7, 2022· Wizards of the Coast
If the spell is countered, the squad ability will not trigger, and no tokens will be created.
No other card is named in this ruling.
#3October 7, 2022· Wizards of the Coast
The tokens created by the squad ability aren't "cast," so any abilities that trigger when a spell is cast won't trigger for the copies.
No other card is named in this ruling.
#4October 7, 2022· Wizards of the Coast
If, for some reason, the creature doesn't have the squad ability when it's on the battlefield, the ability won't trigger, even if you've paid the squad cost one or more times.
No other card is named in this ruling.