20 cards where the set is “uma” and the cards were printed at a new rarity and the rarity is equal to Common

Lotus-Eye Mystics (Ultimate Masters #23)
Mammoth Umbra (Ultimate Masters #24)
Resurrection (Ultimate Masters #30)
Skyspear Cavalry (Ultimate Masters #36)
Tethmos High Priest (Ultimate Masters #40)
Wandering Champion (Ultimate Masters #42)
Foil (Ultimate Masters #55)
Moan of the Unhallowed (Ultimate Masters #107)
Offalsnout (Ultimate Masters #108)
Slum Reaper (Ultimate Masters #114)
Arena Athlete (Ultimate Masters #123)
Molten Birth (Ultimate Masters #140)
Reckless Wurm (Ultimate Masters #144)
Sparkspitter (Ultimate Masters #149)
Groundskeeper (Ultimate Masters #168)
Miming Slime (Ultimate Masters #173)
Dimir Guildmage (Ultimate Masters #213)
Fire // Ice (Ultimate Masters #225)
Canker Abomination (Ultimate Masters #212)
Vessel of Endless Rest (Ultimate Masters #235)

Though this query has ended, its relics still slumber in New Argive.