Karn is an extremely powerful tool
There are several other cool cards that can be added to Scions and Spellcraft, including Rewind, Jin-Gitaxias, Slaughter, Turnabout, Baleful Mastery, and Deadly Rollick, but these first upgrades to the Magic: The Gathering precon for Final Fantasy should already make a notable difference
(2015-08-25) If a spell with awaken has multiple targets (including the land you control), and some but not all of those targets become illegal by the time the spell tries to resolve, the spell won't affect the illegal targets in any way
Impulse drawing each turn has meaningful synergy in red, and making creatures unable to block can be a finisher in the right circumstances
Im not sure this is the kind of randomness we want from the game