Ha ha ha

thanks for the info Micah!
I spent a bunch of time in an LA Ulm game prepping for a battle, making sure I cast Tempering the Will twice before Antimagic was cast, so that Tempering the Will would give me +4 MR while my MR was still low, and then Antimagic would stack on top of that.
I never bothered to check the stats in the battle, foolish me!
On units boosted by the Tempering the Will, Antimagic did nothing

. Damn, I could have used a few more Blade Winds!