Final Fantasy 7 Ever Crisis - Extra Quest (vs. Dyne)

guide.
build : alot Hp + Pdef + Bio Materia
strategy :
Dyne not poison immune. save 6 - 9 atb to cast Bio materia. if, 1x Bio not success.
when he cast pdef buff (3 steps). save your atb for circle sigil break. after sigil phase, you must healing or cast pdef buff. save summon dmg for last phase (it's to end this..)