final fantasy mtg cactuar - 100+ Deck Box Foil Jumbo Cactuar M/NM Magic:

The power to be selective about what you clone and even create more than one copy of particularly strong creatures makes this a truly potent card

An XRR spell is a long way from mana efficient, it never really gets to being efficient either, even when it does double damage

Each of those options is a mode

Wizards of the Coast are giving these products to designers who obviously know and care about their theme while still keeping things within the design space of Magic itself

Hullbreaker does incentivize you to play cards like Consider and Expressive Iteration so that you can easily trigger it and then chain it into additional spells