21 cards where the set is “mat” and the cards can be your commander

Arni Metalbrow (March of the Machine: The Aftermath #16)
Calix, Guided by Fate (March of the Machine: The Aftermath #26)
Danitha, New Benalia's Light (March of the Machine: The Aftermath #29)
Jirina, Dauntless General (March of the Machine: The Aftermath #32)
Jolrael, Voice of Zhalfir (March of the Machine: The Aftermath #33)
Karn, Legacy Reforged (March of the Machine: The Aftermath #49)
Kiora, Sovereign of the Deep (March of the Machine: The Aftermath #35)
Nahiri, Forged in Fury (March of the Machine: The Aftermath #36)
Narset, Enlightened Exile (March of the Machine: The Aftermath #38)
Nashi, Moon's Legacy (March of the Machine: The Aftermath #39)
Nissa, Resurgent Animist (March of the Machine: The Aftermath #22)
Niv-Mizzet, Supreme (March of the Machine: The Aftermath #40)
Ob Nixilis, Captive Kingpin (March of the Machine: The Aftermath #41)
Pia Nalaar, Consul of Revival (March of the Machine: The Aftermath #42)
Plargg and Nassari (March of the Machine: The Aftermath #18)
Rocco, Street Chef (March of the Machine: The Aftermath #44)
Samut, Vizier of Naktamun (March of the Machine: The Aftermath #45)
Sarkhan, Soul Aflame (March of the Machine: The Aftermath #46)
Sigarda, Font of Blessings (March of the Machine: The Aftermath #47)
Tazri, Stalwart Survivor (March of the Machine: The Aftermath #6)
Tyvar the Bellicose (March of the Machine: The Aftermath #48)

The arc of my blade has carved a path of light to the end of these results.