I can Showdown for 2 and save a creature from combat or some kinds of removal
Also, there are lots of X spells that create creatures at instant speed, like Call the Coppercoats, Decree of Justice, White Sun's Zenith, so you could set up an easy win in EDH by casting a big spell, attacking the next turn, and untapping to win
Then if a noncreature card was discarded this way, put a +1/+1 counter on each Moogle you control
Although this ability only triggers when Mirri attacks, you'll undoubtedly be beefing her up with equipment, and first strike will deter opponents from blocking her
The cards and products that come out on August 18th and September 1st on the release date should be the same as later prints