(Namely that Immersive Meowth card.) This means you really need luck on your side to complete this Secret Mission
Modified Matters Since backup adds +1/+1 counters to creatures, that counts as modified, and there are some sweet cards from Kamigawa: Neon Dynasty and Neon Dynasty Commander worth considering for the deck
Numerically, this usually works out to be between 6-10 cards for me, especially if my commander has black in their color identity, and this seems to be a fairly common range for many other players as well
Thorn of Amethyst lets me keep casting my irresponsibly giant green creatures without the added cost of Sphere of Resistance
They have a similar color intensity and brightness to the lands from Unhinged , and the large mana pip in the center helps emphasize each color further
I believe there is much greater upside and lower risk to the former