Any cards clipped in a Challenge can be returned to your hand if you manage to get Dr
Spore Frog to fog every turn, Seal of Primordium to keep wiping out artifacts and enchantments, Pernicious Deed to keep board wiping, Plaguecrafter to keep them sacrificing creatures or Planeswalkers its strong stuff when it gets going
Barring Riftsweeper, Misthollow Griffin, or the actual commander, you can take out virtually anything
Ultimately, I came to the same conclusion everyone else does who has this experience once in their Magic career: Slivers suck
This might not seem like a big deal to everyone, but if you were around when Thirst for Knowledge was restricted in Vintage, youre likely as excited as I am to start Cubing with Thirst for Discovery
That said, buying specific foil singles is almost always more efficient if you know exactly which cards you want