Well, pretty much just the Dimir colors, which you're depending on for your win cons
Then you can -2 him to sac an artifact and recur one, like the classic Goblin Welder or Trash for Treasure
You can also file spells that protect your creatures in this slot because it interacts with your opponents interaction, like Tamiyo's Safekeeping
While each release had its fair share of bangers and hidden gems, there are some cards that standout to us as the clear frontrunners in power level, what they offer to the format, or even in infamy
This sounds like an infinite combo in the making and all I want to do is build a deck that makes it work
Cavern-Hoard Dragon is the first that comes to mind, and it also allows you to cast it for way cheaper if one of your opponents has too many artifacts