If a replacement effect (such as that of Leyline of the Void) causes any of the sacrificed creatures to be exiled instead of put into a graveyard, those cards aren't returned to the battlefield.
Being able to turn already powerful cards like Dismember or Toxic Deluge into more cards feels great because you won't be exhausting all of your resources when you remove creatures
Access to all five colors grants access to the best reanimation targets in the game and the most efficient means of getting them into your graveyard, likely through the dredge mechanic or self mill effects
The lesson: always know what a platform is actually showing you before you trust the number
Along with that, they also grant each instant and sorcery in your graveyard flashback, with the cost being equal to its mana cost
While you control The Darkness Crystal, abilities that trigger whenever a nontoken creature an opponent control dies won't trigger because that card is exiled instead
