Remaking the Spurn Mechanic

Ultimately I've decided the "spurn" mechanic simply doesn't work the way I had initially intended--as a bonus reward for good timing with instant-speed spells. "Good timing" is not necessarily the same as "in response to an opponent's spell." I had to get that through my head, particularly when thinking about the phases of combat.

So I'm simplifying spurn so that it's a bonus triggered effect if an opponent has cast a spell during your turn. It emphasizes the idea of defending and punishing your opponent when he or she attempts to use spells to come after your stuff.

So Warned by the Wind becomes this:

Mechanically this essentially helps protect one of your creatures from removal during your turn, and if it does so you get a tempo bonus against your opponent. It can still protect your creature during your opponent's turn, and I think the cost keeps it playable (especially in limited).

Changing this wording also lets me spread spurn into sorceries, which right now have pretty much no identity in this set. Here's white's "kill everything" spell in this set.

I can see skilled players trying to tease out a combat spell or removal from opponents by attacking and then dropping this spell after combat. But even without the spurn trigger punishment, obviously this is a good spell. I may be undercosting it. The rule templating may look strange on a sorcery, but that's in the event some other ability allows the spell to be played at instant speed.

I'm still thinking there aren't going to be huge number of spurn abilities, compared to the other triggers. If we have to add .5 mana (or whatever) to balance every spurn spell, it can put a real hurt on white and blue. And the blue-white shell is very control-oriented this set. It needs to be able to survive mutants.