Blast of Genius: There are a lot of good things you can do for six mana, and when you draw and discard and already have six mana in play, youre generally not interested in discarding the most expensive spell you have
Off the top of my head some commanders you don't want to see copied a bunch of times - Nekusar, the Mindrazer, Neheb the Eternal, Prosper, Tome-Bound, anything with crazy triggers has the potential to become game ending
however, they did initially set it off to defend the plane, not harm it
Having my [card]Reach of Shadows[/card] manifested was one of the worst feel-bad moments in my entire time playing in the block so far
However, the same doesnt apply for -1/-1 counters, specifically
Why are Pokmon cards so expensive today