That emblem is a solid way to punish decks that want to take a billion turns against you, and her -3 is a powerful sweeper
Game Changers will catch the most egregiously powerful tutors, and otherwise the amount of streamlining and linear gameplay that is dictated by tutors can be neatly sorted by the existing Bracket structure
[-2]: Create a 2/1 blue Ninja creature token
This four-mana blue, black and red 3/4 has Menace, so its hard to block, and it has a big old chunk of text
Almost all Eldrazi decks will play green, with RG having cheaper, more aggressive cards and UG having more ramp, draw, and defense
Hexproof addressed that issue but created its own: piling a bunch of improvements onto the same creature that an opponent can't interact with