Formation Breaker — ruling 1

You compare Formation Breaker’s power to the power of any creature trying to block it only as blockers are declared. Once Formation Breaker has been legally blocked by a creature, changing the power of either creature won’t change or undo the block.

Formation Breaker : règles, fonctionnement et interactions (MTG)

Formation Breaker 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

Creatures with power less than this creature's power can't block it. As long as you control a creature with a counter on it, this creature gets +1/+2.

How it works : Formation Breaker

Original English text — Wizards of the Coast / Scryfall

#1April 4, 2025· Wizards of the Coast
You compare Formation Breaker’s power to the power of any creature trying to block it only as blockers are declared. Once Formation Breaker has been legally blocked by a creature, changing the power of either creature won’t change or undo the block.
No other card is named in this ruling.