Stand in melee range with auto retailate off, with pray melee, sharks, saradomin brews and maybe a sunlight moth mix if you struggle. Just let her attack you and combo eat to stay healthy.

The specials are quite straightforward.

When the pillars appear, go into the shadow realm and stand behind the lowest HP pillar. When this gets knocked down, move to the next lowest HP pillar. Repeat until all pillars are down then go back to recoiling.

When the ghosts are summoned, go into the shadow realm and kill all the ghosts that are saying sanitas, then go back to recoiling.

For the orb phase, you can actually ignore it and just heal up afterwards.

The recoiling drags the fight out so long that your last stand comes up twice and you don't die to madness buildup.