Riddleform and Seasoned Hallowblade are solid, and Miscast is essential, but Essence Scatter would probably be better as another bounce spell, Drannith Magistrate might not be necessary (the deck already felt solid against Adventures), and Shell Shield can be a bit clunky and might be better as more copies of Seasoned Hallowblade or Riddleform
If your bear lizard mutant leaves the battlefield, its treated as a new game object when it comes back, so the counter resets to 0
Rotfeaster Maggot exiling a Soul can be a huge swing in the game, but you've got to find a moment when your opponent is tapped out to make that work
Anything to do with Yawgmoth is awesome, and this card is no exception
Enchantment creatures you control have deathtouch, lifelink, and hexproof
The difference between the two cards is small, but significant in several ways that can be difficult to discern until you play with both of them, which Ive been doing in Blue Moon for a couple months now