MoA quickly flies out of the way, but in Zane's distraction, the demon leaps on top of him, pinning him down, making him vulnerable for her final attack. "Sword of Chaos!" She yells, stabbing him and the demon through the heart.
This is specifically god-modding. You cannot say that the torrent of water automatically connects, that the demon is automatically able to pin me down, or that your sword strikes automatically. I have been trying to write around it, but it seems that maybe you were not aware of it, so I'm pointing it out.
Think about what I wrote. I didn't specifically land any hits. I said what I
intended to do. I sidestepped the demon's charge and swung at him, unleashing a blast of energy at the same time, which was headed for you. Imagine how different the narrative would be if I instead said that I cleaved the demon in half, and the resultant shockwave removed one of your wings.
The difference is that what I wrote allowed you to react to my attack. You were able to fly out of the way of the shockwave. The only way forward in the second example is to either accept the hit and move forward with it, or to miraculously turn back time. Neither is fair, to either of us.
I'm going to roll with this one anyway, because even IF Zane had actually been distracted (which he was not; that was a single, calculated maneuver and he is laser-focused; if you'd let the battle proceed he would have gotten less focused but more chaotic), and IF the demon was able to pin him (yeah, if the demon was able to catch him, he probably would be able to, but Zane's advantage is in his speed), and IF you were able to strike me through the heart (if the above conditions were correct, that's feasible, but I could have wiggled even within a pin to have you strike a lung or something instead), he still wouldn't be dead. But please try to avoid this kind of writing again.
Just leave it open-ended, so we can both have fun.