A mix of both is certainly crucial to supporting decks with needy mana requirements
(Foil) Jeskai Striker precon Kamigawa: the Manga: the Cards Kamigawa: the Manga: the Cards (Foil) Lorehold Spirit precon Mardu Surge precon Miracle Worker precon MSCHF Obscura Operation precon Obscura Operation (Minimal Packaging) precon Peace Offering precon Play Booster Pack Riders of Rohan precon Science
However, the actual cards have the ID of 2/C1 meaning the second card in the 1st Challenge set
Bonus points if the cards are relevant in multiple formats, such as Standard, Pioneer, Modern, Legacy and Commander, as this will help maintain long-term value
Although the rules may seem complicated at first, they are actually quite simple in practice once players get the hang of it
For example, take a Commander heavyweight like Blood Artist or Zulaport Cutthroat