If a core set needed new designs to better deliver on what it was doing, it needed to have the ability to do that
You can look at the top card of your library, and if its an artifact or colorless spell, you can cast it
If you are, though, then its safe to say that these are some sweet new shells for fun archetypes
A couple of cards like Involuntary CooldownInvoluntary Cooldown have taken stun counters a step further to let you put them on artifacts too, which is very nice, turning off mana rocks or vehicles for a turn, and after jumping through quite a lot of hoops The Watcher in the WaterThe Watcher in the Water will stun a nonland permanent
End Step The Masamune is certainly going into every deck with Sephiroth, just for the sheer pleasure of having him swing his iconic sword, not to mention its ability synergises perfectly with Sephiroth, One-Winged Angels emblem