I happened to open four copies of Karumonix, the Rat King on Arena and I keep looking at the Standard-legal rats and thinking there’s almost a passable deck there. Does it want to be toxic with Blightbelly Rat? Does it want to be ninjas with Nashi, Moon Sage’s Scion and the otherwise unexciting Nezumi Informant and maybe go into blue for Silver-Fur Master? Is it worth it to run Okiba Reckoner Raid even though Karumonix can’t find it (I’m like 99% sure)? There’s plenty of black removal to fill out a deck like this; I just don’t know how to build the creature half.
MTGGoldfish lists some Commander/Brawl decks with Karumonix, but nothing in Standard.
Yeah, it’s kind of weird that I’m thinking about spending wildcards on a Karumonix deck when there are Tier 1 decks that I’m interested in and can’t build yet. Though to be fair, I’m like that with physical cards too. Definitely have some that I should have sold years ago, only I keep thinking I might use them.
Testing cards against Sparky is a good idea. Would save you from the situation where you craft four copies of something only to realize that you misread what it does.