It mostly shines in dinosaur decks and out of the sideboard against blue decks
Its a source of self-mill, a source of graveyard shuffling, even a win condition with enough mana
Whenever you cast a spell, if the amount of mana spent to cast that spell is greater than Liberators power, put a +1/+1 counter on Liberator
After all, to steal a spell you first have to survive having it cast against you
(Yes, you can play a commander just for the colors, but that is boring and I dont want to talk about a weird Vintage variant where you have a random card dictating what goes into your deck for no reason.) The most notorious commanders are central to the deck for the consistency and synergy they provide
If a few years ago you told people that Colossus Hammer was going to be in one of the best Modern decks a lot of players would have scoffed