Competitive players frown upon counterfeit cards, with a ban by WotC in place that can cause a player to be excluded from the competition, or worse still, all future official competitive play
As such, the deck isnt too different in practice from Necron Dynasties, simply adding in whites abundant focus on small creatures
So if everyone in your playgroup is down with Playtest Cards, play them
Shadowspear Shadowspears low casting cost, reasonable equip cost, and the plethora of boons it offers an equipped creature hearkens back to Basilisk Collar, a card that saw years of tournament and Commander play after its release in Worldwake
On the play, it can end the game before your opponent can possibly react, outside of free counterspells like Force of Negation
Given that decks that play Ragavan usually play four copies of him, saving yourself around $140 on just one playset seems like a nice win for Rakdos Midrange players (in a post- So what dropped this little guys price by almost 50%