If a copy of that card exists with the right regulation mark, it's still playable
Of course, this will see play in Dragon decks that just want to fill the skies, but its nothing exciting
Cabal Therapy is the best black card because it is thematically on point, perfectly costed, seismic in its ability with flashback, and can be run as a four-of in Premodern
Alchemist's Vial Altar of the Wretched Architects of Will Arcum's Astrolabe Assassin Gauntlet Baleful Strix Barbed Servitor Bladecoil Serpent Blood Fountain Blood Servitor Bomat Bazaar Barge Brass's Tunnel-Grinder Candy Trail Circuit Mender Clockwork Servant Combat Thresher Cryogen Relic Detective's Satchel Detention Chariot Elsewhere Flask Energy Refractor Eye of Vecna Filigree Familiar Gleaming Geardrake Glimmer Lens Golden Egg Guild Globe H.E.R.B.I.E
Instant Color tag templates(None) Eladamri's Call Search your library for a creature card, reveal that card, put it into your hand, then shuffle
This a beefy 5/4 for five mana that can swing and win games with a cool ability, so don't sleep on Twinblade Assassins