Collector Boosters are possessed with rare and/or mythic rare cards guaranteed, plus traditional foils and special treatments you wont find anywhere elselike a Serialized Edgar Markov card, the first vampire of Innistrad
Temporal Cascade or Reminisce, for example, are important in order not to perish due to a missing library
Note that it doesn't deal damage to commanders, so there might be some targets you really need to hit that it misses
At the end of original Zendikar block, a monster race called the Eldrazi, who had been imprisoned on Zendikar, escaped from captivity and ravaged the plane
For example, Dimirs Underground Sea counts as both an Islandand a Swamp
The other two will be composed entirely of reprints, given shiny new Sonic skins