Here the Z-Sigil won't affect the set or weapon used.
This fight is special in the way that Raw is better than element since her elemental hitzones are really bad. Therefore your best choice of weapon is the Apophis Sword "Clear".
Sigil 1: [ SnS Up 15 | Beam Slash | Raw SnS Boost ]
Sigil 2: [ Attack 15 | Attack 15 | Attack 15 ]
Sigil 3: [ Attack 15 | Attack 15 | Attack 15 ] or [ Attack 15 | Duration 12 | Wait Time 17 ]
Use the Power Crystals during her phase transition. Affinity Drinks will not due much here because of the very high affinity of the weapon and rest of the set.
First thing I want to mention about this fight is that it has a lot of phases and the first move of every phase is scripted. This means that you can get her into the blue phase really consistently and without much rng. In the phases that aren't scripted however she has some moves that are really though to avoid consistently and once I figure out how to do that I'll let you know.
I would say this move has 2 variations. Both share the same tell on when to dodge which will be shortly after the rocks/spikes hit the ground.
This move has 3 hitboxes total, if you stand on the outside of her legs you'll only have to avoid two of them. With SW the animation cancel can really help especially if you stand next to her right leg like in the clip.
This is the exact same move that Musou Zeru also has. The windup is long enough to get a beamslash in and then evade twice while ideally getting hitlag for the second evade. Here specifically try to get her to dash into a wall so that you don't lose too much time chasing her.
Be very careful of his landing here, it will oneshot with adrenaline which is why I evade slash it that point in the combo.
Evade slash when she does the laser -> upslash -> evade slash her landing -> beamslash -> evade slash -> uplslash -> beamslash -> evade slash the explosion.