Similar to The One Ring, these cards were colorless artifacts that made it easy for decks of any color to draw lots of cards
Regarding that, I see how the plot cost compares to the casting cost of a card as a significant factor in how these cards play and should be played
They can be solved fairly easily, and, unless combined with the other half of their combos (proliferation of counters, Mycosynth Lattice, Wheel of Fortune), dont have a huge impact on the game for more than a couple of turns
As we know, doubling anything can get you ahead fairly quickly
You might also want to try Citizen Sleeper if you like sci-fi
By far the most fantastic creature in this set