Set Rotation is when after a certain amount of time, older Sets become illegal to play in the Standard format
Just be sure not to deck yourself in the process
The difference between 12 mana and 10 mana for Ulamog, the Ceaseless Hunger, even for Tron decks in Modern, is huge
Offspring is similar to lots of other mechanics in Magic, but the way it could be used could make it an all-timer for the game
(It can't be blocked except by two or more creatures.) If the target creature isn't both attacking and equipped when Item Shopkeep's ability tries to resolve, it won't resolve and none of its effects will happen
That'd be great on its own, but Ancient Cellarspawn also causes an opponent to lose life equal to the difference between the mana you spent and the mana you should have spent without all the discounts