I'm going to throw the initial idea I had when I saw this up here, and maybe keep editing this comment for brainstorming as I go along.

I'm actually kinda wondering if we couldn't go the wrong way around on this--figure out regular ol' blue lyrium is alive, then get to the idea it's Blight making the red lyrium be all busted. Admittedly this is the way harder direction to go because: how are you gonna notice the blue sing-y rock is alive, huh? But there you go.