The summons used in all the decks, but most prominent in the Final Fantasy 10-based Counter Blitz, are reminiscent of the Sagas of Kamigawa: Neon Dynasty, except that they start as enchantment creatures and are sacrificed after three turns
Like Myr, it's still an easy target for Ancient Grudge, but at least with Sphere half your mana base won't be blown up by a Day of Judgment
If you visit Swinging Ship multiple times before the first combat phase of a turn has ended, that many additional combat phases will happen, one at a time
This one's no surprise if you've gotten the latest set of Commander precons, but if you're running four or more colours then this is a phenomenal rate for a big power boost
However, if even a single card falls off your head, you have to exile all of the cards and sacrifice this enchantment