"He's not afraid to die, he's afraid to live! He is corruption, he is stagnation, and he has no place in this or any other reality!"

Badwitch and Wavelength allow Alex to draw connections between herself, other objects and people, or both. she forms a connection between their own power and the sword that Ensara created for her, infusing its anti-demon properties with the properties of her own white flames that are anti-thetical to chaos in general and Nurgle in particular

The defenses the others have established are sufficient for her purposes, so she then lands and stabs the blade into the ground and then forms a connection between it and the fabric of the Warp itself so that she may channel the White Light directly into the Warp, augmented by the holy properties of the orichalcum blade, to try and purge Nurgle's influence directly.