LTalon

So my friend and I were playing around with Training Mode with Bullet and Ragna and noticed something unusual: his combos (with Bullet) were triggering Ragna being vulnerable to Astral Heat after roughly 5.9k damage (at around 41% HP). This, of course, doesn't check out with anything the math on the wiki says, or our research, and we tried it with several other combos, and other characters (Amane and Valkenhayn primarily), and they were all fairly consistently on some combos becoming vulnerable to Astral Heat at around 41% HP. What gives? Does anyone know what's going on here?

I managed to download Marie, and it says it installed, but no real change seems to have occurred in my game; my roster in any mode does not seem to include her. Anyone have any idea what might have gone wrong?