I had forgotten it, so I'm glad you mentioned it. However... You said that you wanted to be high enough to be able to create your burst 2 in O15 and catch people in it. That's 20' high at minimum by my reckoning, which gives you LOE to O15 at 10' high. If you're at that height, then you don't have LOE to M16 at 5' high, which is the first square Hertrud enters that would be within your aura. Auras need LOE to work, like any other area effect. If you're higher than 20', then Hertrud is out of range of your aura. So, no aura damage this time. But thanks for reminding me.