Amazing work. I've heard and seen countless trauma stories about trying to beat DDS and how long they took to actually do so. Seeing it done in only sub-20 minutes is one hell of a feat (especially given how hard it still look and the possible ways it could have gone wrong as you've listed in the description). Again, amazing work here and well done.
Yes, if Pixie had got sleep on Serph it would have been fight over, however Dormina has a 30% chance of hitting, since Serph got "lucky" earlier in the fight, it is unlikely he will be hit again. If you are interested, I also did a Low Level(Level 55 party) of this fight with Serph locked to Human Form(ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-LQTeLkw1AA0.html).