>>5310603I'm of the hope that there's a mechanical way to boost their powers or turn them on and off. Much in the same way a Psyker can grasp his hand on a powerful relic or charged crystal or even sometimes a warp generator
In this case, mimicking Necron Null Field generators
https://warhammer40k.fandom.com/wiki/Null_Field_MatrixBy charging energy into blackstone and/or the nulls themselves, we can both amplify their aura as well as render the blackstone extremely resistant to having its polarity switched. This is why stuff like Necron Pylons are so anathema to them, even to one blessed by gods like Saint Celestine or Abaddon, because they just supercharge them so much its virtually impossible to flip their polarities. Basically the difference between a natural magnet and an electromagnet.