As a rule, it ranges from cheap and narrow effects (Ceremonious Rejection, Negate, Revolutionary Rebuff) to high power with higher costs (Insidious Will, Summary Dismissal, Confirm Suspicions)
It's an okay option for Exhume decks, but otherwise we're all set with our discard engine
As youre going, write down your ideas in a list so that you remember all the traits when you go to draw it
Chain of Vapor Blue has a variety of Unsummon variants that return creatures to hand
This is actually a relief to know because then the mystery would be why the Game Boy artwork even looked the way it did at all
If you have full sets of a certain subset (such as basic to stage 2 Pokmon or Trainers cards), it might also be prudent to not just separate them, but also use that to distinguish that bulk pile