Because of its massive size, trample, and infect, Blightsteel Colossus can eliminate one player from the game in a single swing
They launch earliest, follow the original set design, and reflect the way the game was initially structured
Its probably more than you own in your collection, and getting your hands on a box early on seems like Christmas morning
Once Brotherhood Spy's ability has resolved, removing the legendary Assassin (or Assassins) you control from the battlefield or causing them to lose the legendary supertype or Assassin subtype won't cause Brotherhood Spy's ability to stop applying for that turn
So, what does it all mean
Costing a measly one ink, Felicia, Always Hungry, provides players with an impressive three strength for such a cheap price