Starfield Vocalist A more open-ended Panharmonicon in creature form, I expect ETB/flicker decks will be interested in Starfield Vocalist even before they consider the cheap warp cost
Runick Flashing Fire - Destroy a Special Summoned monster, banish 2
Best Flash Enabler Payoffs There are lots of cards that directly reward you for casting on opponents turns, like Blightwing Bandit, Alela, Cunning Conqueror, Faerie Tauntings, and Gandalf of the Secret Fire
What is the strategy behind Anowon, the Ruin Thief
Considering Steel Leaf Champion is legal in all the same formats, it's hard not to argue you should be playing it instead, considering you don't have to jump through any hoops, and it can't simply be chump-blocked by small creatures