You can enable void in a variety of ways: by sacrificing permanents, warping creatures, trading in combat, or using removal
This card is noteworthy for many of the same reasons that Charizard is, particularly holographic ones
These boosters fill the slot previously occupied by Welcome Decks
The deck truly comes online once Leafeon is out there
Not only does your instant or sorcery go to the graveyard, but your flashback cards count as potential life loss for opponents, and even two or three represent a big chunk of life to keep creatures around
Like other 2020 mechanics, its a bold innovation that interfaces with a core part of Magic gameplay, ensuring it will be interesting and relevant in any game of any format