Its traditionally a Jund card above all else, but its seen play in all sort of aggro and even control decks as well, so it hits all points of the spectrum
The card itself is pretty cool too, providing loads of value by letting you draw cards and move damage around
Desecration Demon decks were almost entirely black due to the mono-color theme of Theros , and the current Standard seems to be heading back in that direction as well
If you can find a way to repeatedly untap it, you take infinite turns, as simple as that
For some analysis on these cards, let's turn to our resident Magic expert Greg Burke, who describes them thusly: "The card is a 4 cost enchantment that when played allows the player to draw 3 cards, and then discards 2
It's a perfect sorcery speed answer