Game Changers are cards on the official Wizards of the Coast list (introduced February 2025 alongside the 5-bracket system) that automatically push a deck into Bracket 3 or higher when present in sufficient quantity
4 is about right to not be a broken source of giant creatures, some of which have really strong abilities
That said, its also expensive at 7 mana, and people will often snipe it to protect their own commanders
6 Rite Of Harmony Rite of Harmony is best used in green-white Elf decks, since the Elf tribe sometimes uses hybrid green-white cards from the Shadowmoor and Eventide sets
That means that if I want to play my own "guilty pleasure" deck - Narset, Enlightened Master (extra turns), I owe it to the table to not play that deck all night long if they really don't enjoy playing against it
In Commander, it might find a home, but there are often better options for both board wipes and protection