The system was originally made as a joke by lead game designer Mark Rosewater but has since become a legitimate way of ranking mechanics from evergreen to never again. Things like artifact creatures or flying are ranked at level 1, which indicates theyre evergreen mechanics
Anyways, I've run Phantom Monster in lots of places, like Pauper online (where it's reprinted as a common a long time ago) or in Commander '95 (where you play cards printed up through 1995)
Given that were in Dimir, well add one more copy card thats also excellent graveyard control: Dimir Doppleganger
Lorcana (lore + arcana) is a magical realm where players take on the role of Illumineers and use magical ink to summon "Glimmers" (copies) of Disney characters from various stories, some familiar and some with bizarre twists, to help them collect lore (victory points)
Amonkhet Raceway seems slightly better than the other two, as haste on demand late game is a powerful bonus