The easiest way to determine if a spell targets a creature is to look for the word target in its rules text
Replacing the typical cast of creatures, Bloomburrow exclusively features anthropomorphic versions of woodland birds, rodents, and amphibians
When you retrace a card to cast it from your graveyard it does temporarily leave your graveyard since it needs to move to the stack to resolve, but it goes right back to the graveyard once it does, or if it gets countered
While the card text specifies that Niv-Mizzet, Dracogenius can only ping creatures or players, the official rules text has been updated to specify "any target." Niv-Mizzet, Parun doesn't draw cards when it pings something, it pings targets when you draw cards
One of the most expensive things in Commander is the mana base, and its because that the more colors you run, the more fixing you need
The idea is simple: Players take two packs of cards, put them together, and make an instantly-playable deck